If you still have SMAPI and its bundled mods installed, you should be able to type debug completequest 9
into the SMAPI console to finish the introductions quest. I'd check it on a new day so it's easy to roll back if it has unexpected consequences :D
I don't normally recommend removing so many mods from an existing save at once, but it's probably fine, just need cleaning up after. Usually with more mods, hehe.
(Just general reminder to the world in general, make sure when you remove any mods that add custom NPCs or locations, that you don't also uninstall SMAPI at the same time, as then it won't be able to clean them up from your save. Divorce a custom NPC you're married to before uninstalling it.)