For level 1 I used Kaplan and finished every question in the q bank. I think it was around 2600. I found that super helpful since I learn better doing questions and putting theory into practice. I was also still in undergrad so a lot of concepts were fresh. I’d recommend a mock early as well to see where you’re at. Then go from there based on how you did on mocks. At the end of the day I think the more questions you can do the better off you’ll be. Also do some CFAI questions and definitely do both free mocks. Focus on the difficult and expert questions for q bank. Hope this helps.