You can probably do either AAMC or TPR. I think I did AAMC 3 (or maybe 4) as my first full length and I didn't feel like it was a waste or like I should have waited. As long as you don't do a ton of practice tests before you're done with your content review, doing a couple is probably a good idea. I did about 3 full lengths before I finished my content review and then did I did the rest after.