Hey, so if i have a ticket issued for two days, can i leave on the first day and then come again on the second day?

Yes you can

I would think so, I don't think there is a hotel in the park.

YES

Yes in many cases you can even come back 7 days later. Depends on the ticket, some of them have a 1 week to 1 month later. Would look into the terms of your particular ticket.