registration concerns

i’m so stressed about registration. for context, i am an upcoming freshman for the fall 2024 semester and i was given an extension for the tuition deposit deadline, so i haven’t had the chance to start registering for classes up until now. I have some concerns… a lot of the classes that are required for my major (FBM) are full. i’ve put myself down on the waitlist, but does that mean i must register for the alternative courses(online courses) incase i cannot get in the class? Additionally, how many classes should i register for? Do students register for classes every semester? Am i supposed to complete all my general ED requirements this year?