I can't see what degree you're going to do, but self studying calc is pretty hardcore. Make sure you check out PatrickJMT, and Khan Academy. Good luck, and try to have fun with it or you won't get very far!
First of all, you don't typically NEED a graphing calculator. You can do better, faster graphing on wolfram alpha. You probably won't be asked to use your calculator to graph anything on tests.
With that in mind, my goto recommendation these days is the TI 36x Pro.
It's what I call an "advanced scientific", which means it does all the normal scientific calculator stuff plus: matrix arithmetic, complex numbers, definite integration, numeric differentiation, and a few other nice features. I find it's interface to be slightly BETTER than some of the low-end TI graphing calculators (despite the smaller screen). AND it's going to be allowed everywhere (even when graphing calculators aren't allowed).
If you want to stick with Casio, the equivalent model is the fx-991 EX (or the slightly older fx-115). It will do everything the TI 36x Pro will do.
Either way, explore your calculator so you can get the most out of it. Either of these calculators can easily get you through an engineering degree, and the engineers work their calculators the hardest. They're also both allowed on the Fundamentals of Engineering and Principles of Engineering exams.
If you insist on a graphing calculator:
There are three categories:
CAS basically means the calculator can do symbolic computation rather than just crunching numbers. Any calculator with a CAS will do everything you need it to an MUUUUCH more. Avoid non-CAS graphing calculators like the TI 83/84. Try not to get too reliant on CAS as you study.
IMO get one of the ones in the last category, and ALSO get an advanced scientific in case you can't use the graphing calculator on a test or something.
My recommendation in this category is the HP Prime. It's NOT an RPN calculator, so you don't have to worry about that. It has a touchscreen, which is less of a novelty feature than it sounds like. The CAS is excellent. The graphing is fast. The display is fairly nice. Make sure you get the HP Connectivity Kit (software) and update the firmware.
Other perfectly valid options include the TI nSpire CX CAS and the NumWorks (python programmable!). The TI nSpire is used by more people, but I really dislike the interface. You should look at the Prime and nSpire before anything else IMO.
If you want to get something cheaper, look for a used TI 89 or TI 89ti. Emphasis on used. They're everywhere, so the prices should be pretty stable. The HP 48, 49, and 50g are options, but they use RPN input (primarily).
Hope this helps!
Longer version of this can be found here: https://www.reddit.com/r/calculators/comments/3hok6z/talens_calculator_guide_v1_xpost_from/
EDIT: CAS is important because it will allow you to do symbolic computation rather than just performing arithmetic.
For example, the result of evaluating an indefinite integral is usually a function rather than a number. The integral of "x2" is "x3/3", for example. In this case, x is a symbol that is being manipulated. The only way a calculator can do that is with a computer algebra system (CAS).
Without a calculator, you must give values for x. For example, the result of a definite integral is simply a number. It's possible to compute that without doing any symbolic manipulation, which is why something like the TI 36x Pro can do it.
The biggest caveat is that it's important to do these manipulations by hand until you're comfortable with them before you begin using the calculator to do them.
Also, while CASs are quite powerful compared to most math-literate people (they know more tricks than I do for example), they DO have limits.
I don't know what major you are but if you are in engineering I would strongly recommend one of these for a little bit more:
Going along with what others have said, here is the link to the TI Nspire CX CAS. It should probably last you for as long as you're taking math classes.