>I am not sure if free tools to make videos are available.

Avidemux for easy editing. Just mark A and B, then hit the delete key, and everything in-between the markers is deleted. Publish the video afterward.

For non-linear video editing, Blender works great. Just drag and drop videos on to the video timeline. Whatever's on top is the video that is displayed during that portion. Blend in/out effects are available.