University?

No, you have to pick your degree as soon as you enroll. That said, you can choose to take 1 'elective' each term, and those choices can be for a variety of skills outside of the skills specific to the degree selected. I always have my university students take an elective every term to pick up some other skills.

Electives count toward the total number of classes needed to graduate, so if you are rushing university, you would complete your degree in 3 terms with 9 core classes and 3 electives. (3+1 per term x 3 terms). If you go slow, you could do it with 6 core and 6 electives over 6 terms (1 + 1 per term for 6 terms) even.

Edit to add: You can switch degrees in between terms if you want when re-enrolling for the next term, but you lose a portion of the 'credits' you've already earned when you do that.