how to create videos for free

Adobe After Effects is the best software for creating video easily with high quality results.
You can also use Serif for creating videos easily and efficiently.

I got X3 as another good video creator software.

Windows movie maker, Microsoft Movie Maker, Apple iMovie, Avid FreeDV bla bla... but all of them will provide normal quality videos.
If you wanted to prepare qualitative videos, you must have to use paidable software. Trial revisions are avail too. You can use them for one month.