Hi,
I'm kind of in a similar place to you re SMPS.
I'd second what Klaus says, and you'll find this as your semester goes on, assuming you have access to teaching material about the circuit in question: the calculated and therefore expected circuit values of voltages, currents, power dissipation, frequency of operation, and other stuff really, all define which components you will be able to use.
After that have fun browsing product parametric search tables on manufacturer's or vendor's websites to find suitable/acceptable re power/speed/price/etc./ + occasional issue of min number per purchase and wondering if you'll ever need another 24 of some obscure component in your life.
Studying how circuit functions and building blocks involved (if not provided, app notes by manufacturers and design notes can be very helpful, even driver datasheets)
Number crunching
COmpensation
Selecting parts (BOM, I think) based on poring over datasheets and perhaps comparing a few
PCB layout
Prototype
End of term report on project which goes towards final grade, no doubt
Other members will know the basic steps to follow you're asking for better than I do.