He is acting really weird

I took little Dinah to the vet yesterday to get his first set of adult shots and ever since we got home, he has been acting really weird. He isn't his usual self. He is so lethargic and scared of everything. He used to walk around and play but now he hides under the bed all day long. This isn't like him. Is it normal for vaccines to do this or should i be worried?

It's pretty normal for vaccines to put cats a little off for a day or two.
If he's still off tomorrow, call the vet.

Yes, he's probably acting that way because he doesn't feel well. If it's because of the shots, he should be much better within a couple days.