New to the app - and I have a couple questions!

I've been using Ladder for almost a week, and so far so good! I tried searching this sub for the answers to my questions to no luck; my bad if I somehow missed them.

1. I noticed some folks talking about going back and forth between teams or doing a two-team split for a season... What does this look like exactly? Does this mean that, for example, I wanted to do Ascend on some days and Align on others, I'd just switch back and forth between the two? Or is there any way to be on both teams simultaneously?

2. Is there a way to access past workouts? Or is it just really week by week (plus the flex workouts)?