I had some food in my garbage in my room and got fruit flies. If I get rid of the garbage and food will they die off/relocate with time?

Oh icky! Not only will you and have you attracted fruit flies, you are also going to be playing host to roaches, mice and flies. Get rid of all garbage and especially food garbage every day, like before you go to bed. Yes, fruit flies live only a couple of days, if there is nothing for them to reproduced onto as well as eat, they die out.

Yes, they only live a few days, even less if there is nothing to eat. They get slow and stupid quickly. If I get a bunch of them I just go around with the vacuum cleaner hose and suck them off the surfaces until they are all gone.

Maybe, but you can speed it up with some shallow dishes filled with vinegar.

Only a little bit is necessary.

might take them a few days to clear out, just make sure they dont have anything to eat or drink ..

They should.