Be sure that an iPad can run the apps you need while in class and on campus; and that whatever Bluetooth case you buy can fully support the iPad such that you can type on it and use it just like a laptop. Don't need flimsy case that falls off or slides down when putting pressure on it during typing or use.
If not, I'd go for a MacBook Air 11" as Karenkcoulter said, or look at a Surface 3 (laptop/tablet). The Surface has the additional capability with the pen, so may be useful for writing on digital stuff, annotating PDFs, class notes, note taking. Certainly there are pens for iPad. Just a matter of how much extra stuff you'll need to get for an iPad to be equivalently functional/capable compared to a small laptop or Surface 3.
If it were me, I'd go for a Surface 3, MacBook Air 11'', or similarly sized/spec'd Windows laptop. This ensures greater flexibility, app and peripheral compatibility; and as Marky noted above - you could dock it with a large monitor, full size keyboard and mouse back at home. As a bonus, if you get a decently spec'd laptop/Surface 3; then you only need one computing device - not two. Something to consider for the college budget if that's a factor for you.