My left front tire is popped. What would be the best way to fix it without buying anew tire?

 

bring it down to the garage and have them stick a plug in it.

 

or put one in yourself if you know how.

 

What do you mean "popped"? If it has a flat, you can plug it or patch it. If that doesn't work, put a tube in it. If the seal around the rim popped. Then, put air in it until it re-seals. But, read the warning label on the side of the tire and don't exceed the max pressure for seating a tire. If all else fails, seek professional help.