I'm so bad at civ

I literally have no idea what I'm doing 90% of the time and I've been playing this game since 2020. I only just found out this month you can theme your art. I seem to only be able to get science and domination victories with Korea on Prince. I've watches a couple videos but nothing seems to stick or its just a bit confusing for me. Any advice? (Literally no dumb questions or advice can be given I'm in the trenches)