It is best to prepare an electronic file ~ including a single resume, the whole resume (including front and back cover, cover letter, basic information, copies of some certificates, etc. ). It's best to print 3-5 copies at hand, and print more at job fairs. Twenty copies. My opinion (or opinion, suggestion) is

If you are not applying for a job in a domestic 1.2 tier city, I think a resume should be enough.

One more thing, if you have more than one major, or you are qualified for many very different positions, you can also prepare your resume for your major or position.