Well in LA I know loads of people who can teach you to eat. It is VERY easy, really you could buy a few torches, some white gas, burn the torches (let em almost die, then blow em out/use a duvateen), repeat 1 or 2 times, then try eating them (let it burn out a bit so less of a flame). Fire needs oxygen to burn, so if you close your mouth around the wick (not on the wick) the flame will go out. For your first time put vaseline around your mouth in case), tie back your hair and for you males out there, shave. Also when you first try this, have someone around who has a duvateen/flame retardant fabric in case of fire catching to anything (shouldn't happen because there is nothing to catch onto). Try not to use a fire extinguisher, the chemicals are bad for burnt skin and should only be used it MAJOR emergency!
Fire breathing should ONLY be attempted by someone who is trained and understands fire (no offense but you brother should NOT be doing it). It is THE most dangerous of the fire skills and half of the fire performers I know wont even do it unless paid $1000+. Not only is there the risk of the fire blowing back at your face due to wind change (happened to my friend who is also one of the best poi/double staff spinners in the world. He has done stuff with cirque du'soliel and other major groups), inhaling fumes from the fuel (often occurs in chemical phenomena, which is not fun. Yes charcoal tablets after fire breathing lower the risk, but I see it happen all the time), you may blow fire and/or fuel onto nearby objects, or the fire can backtrack and collapse a lung if you inhale. Fire breathing is not a skill to be taken lightly. If you want to learn, play with some other tools and you will meet skilled fire breathers who will teach you (you wont have to look for them). Sorry to be a buzzkill