What is the general process of large-scale campus job fairs? Do you need an on-site interview? Or just send a resume?

First of all, you need to buy tickets for the campus job fair and find your favorite company to submit your resume. When you submit your resume, the staff there will chat with you and learn about your personality and professional expertise, which is equivalent to an interview. Usually they just ask casually. It doesn't matter, the main thing is to answer sincerely and find out what you need and what the other person needs, so that you can work for a long time and turn your work into a career. Also, you can prepare more resumes then.