Hello and help please

[Buckmaster]

Hi folks
My son received a tadpole/frog from his pre-k class. I don’t know what kind of frog it is but it’s been living in a small plastic container for a month or so and it needs a home. I hoping someone here can help me identify this critter and help me set up something suitable for it to live in. I have a 20 gallon tank not being used and some random fish tank decorations but that’s about it. I’d like to not spend a fortune if I can help it. Just something suitable to be fair to him.
Thanks in advance for any help you can offer. I don’t know anything about frogs.