WeVideo
However, the free form of WeVideo is not unlimited.
An important drawback is that you now provide 10 GB of cloud storage.
If you are making a one-time video, this is great. However, if you want to edit multiple posts or videos, you will need more space.
In addition to the free form, WeVideo puts a watermark on your videos, which is not great.
WeVideo is additionally available as a personal computer product and comes with free and paid plans.
For a general breakdown of the contradictions between these plans, you can look at their price page.
This program effectively covered the coolness of your choice photos. However, consider that you can shoot the video of your choice.
PicPlayPost
PicPlayPost is a basic program that allows you to do exactly that. Just note that the sound from the two videos will be played at the same time, so make sure that they do not conflict with each other.