First Time Pet Trimming Owner Questions

I got a pet Trimming recently (love the little guy) but its a little skinnier than the images of trimmings its age I've seen, I'm not sure if I'm not feeding it enough or if its sick maybe? Also minor complaint but its missing two of its legs and the person who sold it to me didn't mention it being an amputee, but honestly that doesn't mean I love it any less!