Medical mj is prescribed by a doctor who has undergone the "training" - such as it is state by state. A regular MD with a thriving practice typically won't be able to write for the med mj license. You will need to find a med mj "clinic" that is basically a cash cow for the owner. Typically a med mj dr visit is about $2-300 for your card for a year. The med mj card gives you access to the med mj dispensaries in your state, and from there, titrating and experimenting with the mj is all on you.
***Note - if you have a job that requires drug testing or a firearms permit, those can be at risk if you obtain a med mj card.
I have had med mj card in FL since 11/18. Its quite a bit of research and experimenting. I have a sensitive system so I note effects of meds pretty well.
IF you can determine the type of strain (theres hundreds) for your particular ills...nausea, pain, emotional care, appetite, spasms...the med mj can be a useful member of your treatment regime. It is not the magic bullet sadly. In my case, it helped tremendously with rectal tenesmus and spasms. Some strains made me pain free without worry or a visit to potty for over 6 hours. However, I was so high and paranoid the tradeoff was not acceptable for me. Good luck!