Hey current M1 here, I have been using zanki. For me I don't like doing the cards until after I've already had everything in the section because my curriculum is set up differently than the creator, and my curriculum doesn't work super well for Anki in the first place (at least for me, to each their own of course). So basically I just use zanki for review to keep up with info from past blocks. when we finish a block, I combine the relevant zanki decks into one "master" review deck, and review that deck about 5 hrs/wk. I leave the other decks alone. I tried doing the current block deck along with classes and while it didn't hurt, maybe even helped some, I don't think it helped enough to justify the time spent on it, and it took a lot away from my review time of past stuff.
When using someone else deck I really think it should be mainly for review of stuff you have already learned, otherwise you are just memorizing random facts. I don't have a set number of cards I do or anything, just do what I can since I'm just m1 and am mostly focusing on learning new material for class. I also just left the settings at default, but I do know some people like to tweak those for optimal learning (might be something that is more important if you are trying to use Anki as your main study tool) I do cards about an hour a day in the morning before starting on current class stuff (unless we have a test, so usually works out to about 5 hr/wk). I'll probably turn the heat up and try to double the time spent on the deck in m2.
That's just my 2 cents and personal way I use the zanki deck. You'll have to figure out your own, and depending on your curriculum (and learning style) it may be beneficial to you to do the decks along with class. Sometimes I think the hardest part about medical school so far has been trying to figure out what works for me personally as far as time efficiency, learning style and personal preference, and understanding what may work super well for someone else may be worthless to you.
Also if you haven't used Anki before, and want to use it in med school I would suggest spending a little time learning the interface before school starts with something like a foreign language. It's not hard to use so no need to spend hours and hours doing that.
Good luck in school next year!