Can somebody please tell me how to properly animate this?

I have downloaded a free rigged model off the internet and wish to use it in unreal. The problem is, it is very small and thus is impossible to animate.

How can I properly scale it? I have attempted scaling it in Blender but when I go to import it into UE4 I get errors. As far as I know if I cannot directly scale the mesh in UE4 either.

Can I animate a small model in some way or am I out of luck?

I have no experience in 3D modeling so please explain this in high detail.

You have to set the unit scale of blender I only no Maya but a quick google search found this that explains it in the first few seconds.
You can also scale any mesh on import. change the import scale in the options when importing, normally if its too small then changing the x,y and z import scale from 1.0 to 100 will normally fix this.

Hope that helps.