It's not that hard, there's lots of tutorials out there. The easiest way to make a stamp is by putting a picture on a stamp base in Paint, making a stamp with animation is hard to make when you don't have Photoshop but I found my own way to make one.
Also, just a suggestion but please try to search things up when you have a question and then ask other people when you can't find the answer or it's really hard to find the answer.
well, since you have photoshop, you should use photoshop instead of paint. I don't really have photoshop ( but my brother does, but he doesn't really let me use it much ) so I usually use pixlr.com, but I guess it's pretty much the same really. You just need to resize or crop it and make it fit on the stamp base.
And for animation, I use ezgif.com to resize, crop, and split the gif. And then I put the frames on the stamp base one by one and save them one by one, and then I combine all of them in ezimba.com. I don't know how to make animated stamps in photoshop though, sorry.
Well, that's how I do it, sorry if it's not clear enough or much help.