A couple of comments: I’m not a fan of “baseline” scores. Prep like you only have one shot at a good score. You can always take a timed ACT practice test to get a feel for your “baseline” score without it being official.
Second, I’m not an expert in the new test format for the ACT so if I was you, I would spend some time researching the issue i.e. what do the new rules mean and what is the effective date, and in what light will colleges view these scores when allowed to take them individually?
I just don’t want you to spend a lot of time taking all 4 sections at the same time (and likely getting a lower overall score) than if you are allowed to take individual sections, one at a time next fall? You are only a sophomore, so maybe make your goal to complete the ACT by spring of Junior year? If you are a strong student you might be gunning for 35/36s in each section as I’m sure your academic peers will be doing the same.