Help!

I rescued this little guy from my barn cat. I’m gonna search for the home and take him to the vet in the morning, make sure he’s okay and find where to take him. I was just wandering what his age is and some basic things I could do to make is night indoors a little less stressful. I also understand it’s not okay to keep baby bunnies but is there an age where it is okay and if so does this little guy look to be it?

by AlexanderIriel