I have searched the forums for posts about camp and summer camp data bases but I haven't found anything that answered my question.
If the questions are what you posed in the first post, then Yes, and Yes. OK, I realize that's simplistic and may not be what you are searching for. I'm wondering if your searches were not quite focused because there are TONS of sample db's based on student/class design. It would be surprising if not one of them was even close to what you need. Not understanding Access very well might be a disadvantage when trying to determine if one is close enough.
Class full - would require a table that lists classes that contains at least a field for maxEnrollment. It might be a sub of a table or field that lists courses, because one day (if not now) it may be possible to run overlapping classes for the same thing (subject/course). These classes would need separate identification. This brings home the point of how important design can be, as anticipation is a good ingredient to bring to the design process.
If a student wants to enroll in a class, you will need to search tblClasses for that student id and see if the start date/time or the end date/time for the class lies between the start date/time and end date/time of any records found for that student id. If yes, there is a conflict.
Not sure if any of this helps. Suggest you try a search for "ms access student class database template" or similar. Even if you don't find one that exactly fits the bill, researching will likely expose you to ideas/concepts that you would otherwise not have thought of.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.