First, if this is your only transportation, leave it alone until you're sure you could borrow or rent a car for a coupla days in case you can't get the bolt back in.
Be aware that there are 3-4 ways to repair the drain plug opening if it is stripped after removing the plug - but you may be delayed a day or more in finding just the right solution.
do you have a 1/2" drive breaker bar? If that won't do it, you may need a 'cheater pipe' or heat as suggested or an impact wrench.
oh and, I'm ashamed to suggest this but, make sure you are attempting to turn it counter-clockwise. (lefty-loosey)