- I personally enjoyed my first playthough more without looking too much at the wiki. YMMV. That being said, I do recommend looking at it to find NPC loved and liked gifts, since there isn't much information on those in-game, especially for non-marriagable NPCs.
Though I agree with everything else you said, and this isn't Wrong per se, I do want to point out that there are indeed hints as to loved gifts all over the place. For marriage candidates, as alluded to, they tend to have secret notes which detail some things they love. For others, conversations with them and others may provide clues. Worst case, you can always give them stuff, they'll tell you how they feel about it, and if you check them on the social tab it'll have info on all the stuff you gave them and how they liked it. So certainly you don't Need the wiki for that stuff unless you want to play "optimally", which, as you alluded to, isn't the most fun way to spend your first playthrough. So I say pay attention to the dialogue and look for hints, and when all else fails, throw stuff at the wall and see what sticks!
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As far as what is "best" in terms of crops and working on stuff, something I love about this game is that there isn't typically one clean answer which is always true, there are multiple paths with pros and cons to them and you can easily argue one or another is the "best" depending on context, prioritization, and preference. This isn't *always* true, late game from a profitability standpoint certain things wildly outclass others, but especially for a new player on your first playthrough at the beginning of the game, options abound. So I'll make an argument for many things as the "best", I'd recommend you take a look and see what most appeals to You, and go down that route. Ultimately you can explore it all as you please anyway so you never need to worry about going down the "wrong" path, you may take longer to hit a certain goal or target than if you had gone down a different route but there's no time limit to the game and nothing is permanently missable.
For what to focus on:
Farming is the best because farming provides the highest monetary return on investment of any activity in the game. The more money you invest into farming, the more money you make, which you can then reinvest to keep compounding your profits until you're absurdly wealthy. Plus, the game is commonly referred to as a "farming sim", so why not farm!
Fishing is the best because fishing provides the most immediate profit of any activity in the game as long as you're even halfway decent at it, and it's competitive for most profitable even if you're not. Especially if you have the skills to catch Catfish from the town's river when it rains, you can make more profit from a day of fishing than you can from a whole crop cycle early on.
Mining is the best because Mining lets you get Upgrades for your tools. Better tools gives access to new resources, and unlocks general progression. In addition, better tools mean less energy consumed to accomplish the same task, which means you can get more done in the day. And, of all the things to acquire, how can anything beat "more time and energy"?
Foraging is the best because it's a skill which is super handy to have developed pretty quickly for a variety of reasons, and focusing on foraging will help you learn the maps. The resources are literally free you just need to grab them. Otherwise, you get foraging experience for chopping down trees, and you ALWAYS need wood.
Friendships are the best because as you develop friendships with the villagers, you'll unlock super useful recipes, learn more about them, and learn more about the world around you. Introducing yourself to them is literally the first task given to you for a reason!
For Crops:
Parsnips are the best crop because they provide the highest percentage Return on Investment over time. They provide a whopping 18% profit PER DAY, as you get back 175% of the seed cost after only 4 days in the ground. They require massive investments of time and effort to fully captialize on their profitability, in order to properly till the soil, plant them, water them, harvest them, and sell them, but if planting and watering crops is what you most want to do, Parsnips is where it's at.
Potatoes are the best crop because they have a 1/4 chance to drop two Potatoes when harvested, and when incorporating that they provide the highest baseline profit per tile per day. If two people planted an equal number of parsnips vs Potatoes, the person who planted Potatoes will take home significantly higher profit. They have a high profit per day from a percentage standpoint as well and their seed costs are quite reasonable, and they're a relatively quick turnaround at 6 days.
Cauliflower is the best crop because it can turn into a Giant Crop if you plant a bunch of them together, which is not only Super Cool, it also means that assuming you get at least 1 Giant Crop from a harvest of them, it's the highest profit per day per tile of any crop available in Spring of Year 1 from Pierre. Plus, Cauliflower has a Huge base value per crop, which means it gains a Huge value increase from processing them in machines like Preserves Jars or Kegs.
Kale is the best crop because it provides the highest farming XP gain per tile per day when grown. So if you don't really super love farming but you want to get good sprinklers (so you can spend less effort farming later on), Kale is the crop for you! It also has the second highest base sell value behind Cauliflower and as such is decent to process, and it's only 2 gold per day per tile less profitable than say Potatoes, so it's not like you're absolutely killing your profitability to grow it.
Rice is the best crop because it doesn't need to be watered, as long as you plant it close enough (within 2 or 3 tiles I think) to a water source like a pond or lake. So after planting it, you literally do nothing but wait for it to be ready to harvest! It's essentially free money and free farming XP!
The crop available at the Egg Festival is the best crop because it has higher profitability per tile per day than Any Other spring crop, even when planted on the 14th of Spring. It's the most expensive seeds available in Spring Year 1, but it's worth it because it provides a huge profit and also it's a fruit, and generally fruits are better to process in machines than vegetables.
tl;dr, what do I do? Well the way I see it, at a bare minimum you should fish when it rains, if you at all enjoy fishing. The best fish are out and about then, you have energy aplenty because you don't need to water your crops. Otherwise, during sunny days you can take care of your crops in the morning, and then alternate between foraging and mining in the afternoons, when not hanging out with Villagers. If one activity calls to you more than another, of course go for it! Again there's no wrong answers.
As far as what crop to plant? If you enjoy farming, go for Parsnips, until you can't plant any more! A poster on here tested playing Spring many times, and for them at least going absolutely Nuts on Parsnips gave them the most money coming out of Spring. Whenever you get to the point where you're using more time and energy than you want watering them, then scale back a bit and upgrade to Potatoes, Cauliflower, or Kale, depending on what you can afford (between Potatoes and Cauliflower) and what your priorities are (between those and Kale). If you can line it up such that you get your crops in a place where you can sell them all on the 12th, that's great! You can get the Egg Festival seeds on the 13th and go from there. Also Rice is Always worth planting as long as you can fit it in near a water source, so any Rice Shoots you find are like bonus profit!
Beyond that, explore and have fun! There's tons to find and do, and the game is pretty good at nudging you towards stuff, so just give everything a try and see what you like! I sincerely hope you enjoy!
That's still tl;dr. Geez.... Fish when it rains, plant parsnips, then potatoes, then save up for the egg festival, and try not to miss giving people something nice on their birthday.