Keeping a salamander I found outside my door?

I found a salamander outside my basement door, the poor thing was basically drying up out there, I put it into a large basin I had lying around with a little container filled with a TINY bit of water, a lot of wet gr, some pill bugs and a few twigs and rocks. It livened up right away! I googled it, and it's a long toed salamander. It's about 8CM long, a bit shorter than that probably. I'm wondering, if I got an aquarium and bought grhoppers, would it be OK to keep it? How old is it, if it's about that big? And if I kept it are there "wild bugs" I could catch for it to eat, like pill bugs?