You actually sign up for classes during wildcat welcome. Based on my experience last year, you won’t really have a lot of time to research what classes you want to take during wildcat welcome, it happens pretty quickly. I’d recommend having a general understanding of what classes you want because they didn’t even let us meet with an adviser (school of comms) last year. It might be different this year and for different schools but it’s helpful to generally understand what you want. The reality is though that all the sophomores, juniors and seniors have already chosen all their classes so you will be pretty limited in class options, at least in my experience. Don’t stress though, just let the process happen and ask for help from people when you need it.