[Eagleeyedan]

Probably the most intuitive program is Autodesk 3DS MAX, which, though it is expensive for the commercial version, the Student version is free. There are no limitations on the student version, it is identical software, but the only difference is the license so you may not sell any work you do in it or make any profit off it. The download link has already been posted above so for sake of redundancy I won't link it a second time. There is also their Maya software package, but 3DS MAX is again IMO the easier program to use.

Blender is another free package, but it is not as easy to pick up quickly without an understanding of 3D modeling procedures and animation techniques as well as basic programming if you want to take it further. 3DS MAX is super easy to figure out quickly and their included tutorials teach you most of what you need to know for the level of animation you need to create a short safety animation.

As a side note, if you go with 3DS MAX, I would suggest the 3DS MAX Design package. It has a lot more features and a huge built-in material library.