Next year I’m taking (or planning on taking, we had issues with my schedule and are trying to fix it before starting school)
AP Chemistry
AP English Language and Composition
AP US History
AP Biology
Pre-Calculus Honors
Health Science 2 (part of my school’s ‘be come a nurse’s assistant by the time you graduate’)
Online:
AP Spanish Language and Composition
AP Psychology
AP European History (0.5 credits)
AP Microeconomics (0.5 credits)
Self-study:
AP World History
AP Human Geography
How many hours of homework per night should I expect? How hard these classes?
It is going to depend a lot on your teachers and how serious you are in the class.
AP Chemistry at my school, for example, gave problem sets with about 15 questions. These questions would have an a,b,c, and d portion which made it take forever. Honestly, she assigned so much homework I just stopped doing all of it. The class prepared me extremely well for the AP test. I got a 4 with no studying except for doing the homework, without taking chemistry beforehand. For me the difficult part was the beginning with the reasoning, but after that almost all problems become straight forward.
AP Bio requires a lot of memorization with minimum reasoning, honestly. You have a huge leg up if you know a lot of greek roots, because a lot of the terms become clear after you know them.
Pre-Calculus in my school had a lot of trig and an intro to college level mathematics because my teacher expected us all to take her AP Calculus class which is the most difficult on school, because of the work load. She was a harsh grader, but the concepts are mostly extensions on things that were previewed in Algebra II and Geometry(assuming you covered the unit circle in Algebra II).
APUSH is mostly memorization and understanding how the past affects the future. It requires you to be able to prove your point with examples that are given, while also having ample outside knowledge to add to that. I think most people struggled proving their point because the readers expect you to analyze more indepth than most high school classes require you. The easiest way to get past this is to write why the example you are using and finishing the sentence, “This is important/significant to my argument because”
It will depend on your teacher. The standard at my HS was 45-60 minutes per AP class, 30-45 minutes for an honors class.
When are you planning on sleeping 
The 2 most difficult classes at my school are AP Bio and AP Chem, Bio more than Chem. They are both taught extremely well, but the sheer amount of work and at home learning is what makes it tough, as well as labs. The teacher also is a huge deciding factor. When I was Honors Bio, homework for an honors was like half an hour a night top, or that was the expectation. Usually, I had at least 45 minutes and usually an hour, though it wasn’t uncommon for more. It depends on the teacher, my bio teacher was great but gave homework for practice and lab reports. My bio teacher said that for the first like 2 or 3 months of school all they did was labs, no tests.