I know and participated in the problem solving of job fairs.

There are generally no restrictions on skills, education or age, but at least he must be an adult. If there are any requirements for academic qualifications, he will write them himself, such as the XX job fair for college students. It's best to prepare all your certificates, diplomas and awards, as long as they are copies, and prepare a clean and tidy resume, not too thick. Job fairs are generally free, at least I haven't met them. There is little difference in general job fairs. At most, some places are more advanced and require more candidates. Just be prepared before you go, think about introducing yourself, and then don't be nervous! Finally, I wish you success!