Gotta be careful with what you get. Bondo is a brand (of course), known mostly for making body fillers, but they make other stuff too. 'bondo' is also the generic name given to body fillers in general often. So, with that out of the way, what you would like to use...
At most places (including Walmart), you're going to see a couple of kinds (at least) of body filler. Specifically in the Bondo brands, you should see stuff like 261 (the can with a lot of red) that is listed as just body filler, and then there's also stuff like 402 (more greenish on the can) that's listed also as a body filler, but with fiberglass reinforcement.
So, point of my blathering: Most of the time, you are going to want the red stuff. The reinforced mixes and applies nearly the same, and it is much stronger, but it is also MUCH MUCH more difficult to sand. On most reworks and repairs, the red will work great without needing nearly as much elbow-grease. If you think you will have a lot of detail work/filling/sanding to do where structural strength isn't that important, go to an auto parts store and get some lightweight or 'featherlight' body filler. it will be a little softer, but will then sand even easier. That's the trade-off with these fillers, easier sanding means a less-strong cured result.
Good luck with it, and Happy Holidays! Oh, and remember that all of these polyester-based mixes are exothermic, they're going to get hot when they cure, so you might want to test a small spot before loading some on and potentially melting something.
