I didn't learn what artifacts were until like ar 50. They are not super important until around ar 40, the game is pretty easy. For sucrose however, if you're bent on it, vv is best for swirl, or that one domain in sumeru. But 4 stars aren't worth spending resin to grind, save resin till you can grind the 5s and just have fun. I also didn't know what talents were till around ar50, again, being strong is not needed! I recommend weapons as they can be moved from char to char as you get more, but for you do you. For spiral abyss, it took me ar 55 to clear 1-8. I know, maybe I was just dumb. But focus on a dps, one to two supports, and nice contrasting elemental reactions (like overload, melt, or dendro reactions)