Source Film Maker is a great software for 3D animation as it already comes with lots of assets from TF2 and a few other games, but there are also thousands of other things for SFM to download off of the workshop too. You can also import your own assets, so you can animate basically anything you want. Learning to animate in SFM is a little tricky, but once you get the hang of it, it's pretty easy. If you are stuck there are many tutorials, and I think Valve even has an official Youtube tutorial series. And if you're still stuck, you can always turn to the large community of people who use the software. Make sure to save frequently though; if you overload it's memory it will crash and you'll want your progress saved.

Source Film Maker is a great software for 3D animation as it already comes with lots of assets from TF2 and a few other games, but there are also thousands of other things for SFM to download off of the workshop too. You can also import your own assets, so you can animate basically anything you want. Learning to animate in SFM is a little tricky, but once you get the hang of it, it's pretty easy. If you are stuck there are many tutorials, and I think Valve even has an official Youtube tutorial series. And if you're still stuck, you can always turn to the large community of people who use the software. Make sure to save frequently though; if you overload it's memory it will crash and you'll want your progress saved.