I’m lost where to start

I have some chronic pain, especially in my lower back and legs. I haven’t worked out consistently for 4 years now, I’m 20 years old at 115 pounds, 5’2. But I want to get better, but I have no idea where or how to start without triggering pain. But I want to be strong and on my feet again. I’m a healthy eater(I love food) but paleo only for I’m allergic to gluten and dairy. Any ideas and help?