Most “free fonts” sites mix free and not-free fonts. They will be labeled as such.
You are welcome to add and use free fonts in this class. If you are using a PC at home and a Mac here, make sure to grab both versions of the font. Keep them on your flash drive (or other portable media).
Some require paid licenses if you are going to use them in a commercial product (something for which you get paid). But any free font is okay to use for school and okay to display in your portfolios.
E-mail me links to other good ones that you find, and I’ll post them here.