if you can find a shop were you can apprentice(thats going to be kinda hard in some areas)as for at advice ,I am a tattoo artist(licensed) the reason alot of forums dont give advice is they dont want alot of folks trying to tattoo and harming people or spreading disease without proper training.
It took me 4 years to find an apprenticeship,so if you are not going to be deticated it might not be the thing for you,but if it is there are several things you can do to prepare along the way.
1.Sketch,sketch,sketch(all things not just what you like)
2.learn as much as you can about equipment(parts ,functions,etc)
3.learn all proper terminalogy(example-tattoo machine not tattoo gun,this mistake alone will kill an apprenticeship,so learn all you can)
4. study other artists
5.if you can practice on your self(not others)my thighs was my practice canvas(my thighs are my time line as i progressed,i can always look back,plus no one ever sees them anyway, always have on shorts in the summer)
6.do something tattoo related every day(sketch,read,study,talk to artist,etc)
7.go to conventions great place to meet artist,show your work find good equipment,etc
8.buy the best equipment you can afford(stay away from beginner kits most are garbage,good work equals good equipment)
Anytime you need help or want to chat drop me a pm