What can I care and train my rescued Jack Russell?

I recently rescued a small Jack Russell. He was thrown away because he is wounded. I took him to the vet and got him vaccinated. But now since I have never been with any kind of pets in my life, I don’t know what to do next. I want help from people who are expert in petting. How can I take care of rescued Jack Russell? What can I do to train him? Can anyone help? I would really appreciate your feedback regarding this. Thanks.