Editing toturial video recorded from the phone and thumbnails designer

I It requires an expert who can edit the software's tutorial videos directly on the smartphone. Project details are as follows:

The videos will be already recorded, but errors and audio gaps must be removed, and attention-grabbing elements must be added. There will be projects in English and projects in German.

The duration of the videos will range between 5 and 10 minutes.
These are three examples, and your results can be better.
1- https://youtu.be/NPtI5qxXeeM
2- https://youtu.be/sZMQeGhHSRo
3- https://youtu.be/KWBY7JyfEw4

I also need a thumbnail designer to design thumbnails for these videos