If your fishing level is low, it makes fishing a little harder. However, you can level up your fishing skill a little faster without having to actually fish, you can get some fish ponds (A building that you can have Robin build) then put some random fish in, and up your skill by taking care of those. Just have patience and use the resources available to ya, like bubble areas in water, things like fish bait and tackles (Depending on your rod you can have bait and tackles), and probably most importantly, the wiki.
Also, if I were you I'd look up fishing tips and basics for Stardew Valley on Youtube, which will also help. That's what I did lol.
Oh also, also, about your candles! If you accept a cat or dog from Marnie (The lady rancher chick in the woods you buy animals from), you can pet your cat or dog every day and that will help you get four candles on the shrine.