When you are receiving unemployment benefits, your local unemployment office may give you leads on jobs they think you may qualify for. You do not have to always follow up on every single lead, but you will need to give a reason why you aren't doing so.
Sometimes you may not have the necessary skills or requirements for a job or jobs your unemployment office has suggested. If that is the case, give that reason for not following up on the job. As far as the job fair is concerned, if you have a good reason for not attending at all, and it has been recommended by your unemployment office, make sure to have a good reason why you couldn't attend.
Do your best to follow up on as many job leads from your unemployment office as you can. Make sure to meet or exceed the number of job searches required each week so that if your schedule conflicts with the job fair, for example, you can show that you were not lazy and that you were involved in other activities that you hoped would lead to a job.
You need not follow up on every single job suggestion from your unemployment office, but do try to check out as many as possible along with your other job search activities, as proof that you are making a serious effort to find a new job. If you do that you should not run into problems with receiving your unemployment.