Now is a great time to get back into it. Man, discovering everything from Adventures forward fresh- well I’m jealous. My personal 3 favorite sets are Empires followed by Nocturne/Menagerie. My favorite mechanics are Debt, Split piles, Landmarks, Events, Ways, Night cards, and Heirlooms.
Anyway, Dominion online used to have a cool feature called “Familiar Cards” that once you set it up (and kept your lists updated) would introduce X amount of new (to you) cards per game, so you could control the pace of new-card-shock. I really miss it; it was great for manually tracking which cards I still wanted to try more.
The feature they have now is the card pool levels. Since you were playing back in isotropic I would recommend jumping straight to level 5 or 6, and play until it’s mostly familiar, then kick it up to the next level and repeat.