My school is on a block schedule and I’ll be taking calc ab. I wanted to switch into APES but I’m already taking AP Chem. Will it get to a point where I get confused between classes or I’ll be fine?
You should be fine; they’re separate sciences.
Having taken and gotten 5s on both I would say you should fine. The only overlap there may be is when you start to learn about chemical pollution but there isn’t really anything that would be detrimental or conflicting there since chemistry doesn’t change depending on what class it is. Even if the classes had a good bit of overlap of concepts there wouldn’t really be anything confusing. Chem is a lot of applications of things you learn while APES is mostly fact regurgitation and very little (I think maybe 1 free response?) actual application of formulas or reactions you learn about. If you ever took or are going to take AP bio then there will be a lot of overlap when you get to ecology but that is a good example of why learning about similar things in two different ways is a good thing. The stuff you learn in either class is completely valid and applicable to the other class. The only classes where confusion between then can become an issue is with math classes if they are about similar but different things. I took differential equations at a local college junior year and some of the people there said that they struggled with the class some because we were learning multiple ways to solve the same problem and they would end up using things they learned in calc instead of diff eq.
The only thing I would tell you is time management. APES had so much busy work (in my school at least. 1.5 hours if the teacher went overboard) but you should be fine. APES is rote memorization and is a generally fun class, you should be fine and enjoy it.