If you are not low on gas, (shake the bike and listen for gas sploshing if you don't have a gas gauge), it is time to clean and rebuild the petcock. Here is a video on how to rebuild the petcock:
It is also likely that you have sediment or rust in your gas tank. Here are 2 videos on how to clean out your gas tank:
If you absolutely need to get home, you can try blowing out the entire fuel line and fuel filter really well. It might buy you a little more time. Remember that if you don't have a fuel filter in, it will be carb cleaning time pretty soon.
Don't feel like you have solved your problem? Click back to home and check for spark, compression, and air.