Career advice do i join the marines?

first of yes i understand its myself who has to choose my own career am only asking for advice so basically am 22 i have trained as a carpenter but its not for me never really enjoyed it to be fair i have never had any ideas of what i want to do for a career left school with not great grades so thought ill get into carpentry after years of doing that it was just getting me down it ain't for me but now am suck i have no idea what i want to do as a career i have been thinking about joining the military(royal marines) but not sure how does one choose a career i don't want to end up in a Supermarket i want a career which gets me respect and shows to people i can me the person they dont think i can be if you could share some advice that be great