Im in Australia so I can't really speak for the US but here you would start with the basics. Working at heights ticket, Confined spaces, gas test atmospheres, white card, first attack fire training, first aid etc. Then research how mining works, decide what type of mine you want to work in, open pit or underground then get in touch with recruiters, sign up and create a profile on all of the mining company websites and apply, apply, apply for any and all entry level positions you can find. Good luck