It's aerospace not medicine, they don't really care as long as your grades somewhat resemble what they're asking for lol
If you want to prepare yourself then yes, get an arduino, learn how to do some programming some form of C (you could do python instead and that might teach you better programming habits but as long as you follow online tutorials for C/#/++ it'll teach you the same stuff plus other more useful things), learn about laplace and maybe fourier, learn about PID (both the theory and implementation). If you do those things it will make your first two years a lot easier, arguably to the point of boredom, but they're things that can easily be learned in your spare time.