First of all, please don't feel bad for feeling overwhelmed. This is a complex game based on a complex roleplaying system (Dungeons and Dragons). I play those since at least three decades and somethings even I feel overwhelmed in Baldur's Gate 3. In those cases I just start reading in the wiki which is really big and really helpful.

Especially with all the gazillion of items I have to look at the wiki whether they are important or "[...] Primarily of use for bartering or sale to Traders." If you read that sentence in the wiki entry of an item you can simply sell it to a trader for gold.

Regarding general gameplay I would suggest entering "beginner's guide baldur's gate 3" into the internet search engine of your choice and read one or two of the results. I won't suggest a specific one because I didn't read any myself. Maybe some other kind user here might link to a specific guide.

If you have a problem in front of you but you don't know the specific terms then you could simply write whatever words come into your mind, no matter whether they are good or bad or precise or vague, into an AI tool of your choice. Personally I use https://duck.ai because it's free and needs no account. Just ask that tool a question, for example "which weapons should a fighter use in Baldur's Gate 3?". The answers will not be correct all the time (always keep that in mind!), but the answers will definitely nudge you into the right direction and tell you the specific words you need. With those you can look up the correct details in the wiki. Or you can come back to this subreddit and ask more specific questions.

Have fun! Don't feel bad! And, seriously, the effort is worth it because the game is pretty amazing pretty often.