anyone know where to pick these up?
Go to your local sign shop. Most of them can print decals and laminate them so they'll stand up to wear and tear. They won't be expensive so just tear them off and replace them if they get messed up.
Our school has a graphic design department, they could design and print those out for you. Check with your art teacher maybe your school could do the same.
Somebody local in town should be able to do it for you also. Maybe a kid on the team has a relative in the printing business.
The problem with those is you have to zoom in to see them, old guys like me would need binoculars to read them!
Looks familiar. Where did you get the pic?
How do you keep paint from covering up the decals when you get the bases ready for games?