To College Students...Please Help

So I will be starting College in MSU and I'm so nervous that it's ridiculous.

I will be majoring in Zoology in order to attend Vet School as a mixed animal veterinarian. A lot of my family is putting so much pressure on me and now I'm so stressed about it that I have no idea how I'm going to properly plan out my education. I'm just starting out with mapping out the subjects I want to take but is there any thing else that I'm leaving out? How often should I work? What do I do to keep myself motivated and stress free or less stressed?

Please help!