autonomic disorder

Hey guys ! I'm 19/F.. So I have a Autonomic disorder and over the past year I have been losing muscle (mass?), I never worked out before, lifting wise but I have done strength tests with my doctor and I have definitely lost muscle, Also I work with kids and I use to be able to throw around 3-4 year olds for a while, but now I can hardly carry a 30lbs 2 year old for 5 minutes without my arms giving out. It's been tough and damaging on my mental health because I can hardly hold this phone up typing this all.

And way I want to fix that! I want to carry the kids at work, I want to carry my son's car seat one day, I want to pick up my wife and back squat her, and throw her around, I want to be able to do these things.. But I don't know where to start, how to do stuff, what equipment is need to buy (I want to workout at home) , and what areas I need to focus on.. I'm assuming my legs and arms? but I don't know. If someone could help me I would very much greatly appreciate it, even if you suggest youtube videos to watch. I'll take anything. I want this!! I want to get stronger!!