Get familiar with Clipchamp:

Import a video

Trimming a video clip

Splitting a video clip

Remove Gap after trimming/splitting video clips

Adding Text to a video clip

Adding filters to a video clip

Adjusting the speed of the video clip

Resizing a video clip

Fill, crop, picture in picture, rotate, flip a video clip

Deleting a video clip

Adding music to video

Exporting a video