2. Campus presentations are basically not on-site interviews, and presentations are all advertisements made by enterprises. You can find reliable classmates to help you submit your resume. If you have to interview on the spot, you can go back if you ask for leave. It is normal for senior three students to be busy with papers and the like. Bosses will understand.
It's easy for interns to resign, and it doesn't involve social security, because they won't do it for you at all. Sign it, get the money and leave.
In this case, you will become a regular employee directly after the internship, and you don't have to interview in a mess. Even if you don't find a suitable job, you still have this job. Do a good job and don't kill yourself.