Want to start working out

I want to bet toned and build muscle, but I have a lot of joint pain, everywhere. My mom keeps telling me that getting in shape will help, but I can hardly even walk sometimes because I’m in so much pain. How am I supposed to work out when every movement I make is accompanied with cracks and pops and stabbing feelings. I went to the doctor and they couldn’t find any problems, but I’m still in pain. Sometimes so much pain I throw up. I still want to get in shape but I can’t bear working out. Idk what to do anymore.