Anyone know how i can work on getting a job in a shop in the United States?

hey, i was just wondering does anyone have any info on how i can work on getting a job in a shop in the united states eventually. Im doing an apprenticeship in ireland and we dont have any formal qualifications per say over here. Im an american citizen and i've lived there but i was wondering is there some kind of regulated structure to things over there or if i was to look for a job there after my apprenticeship is there some kind of process id have to go through? thanks