A good starting hourly rate is around 25-40$ an hour. Most projects are around a week long.
Once you establish yourself and get repeat clients you can begin to charge more. Some editors charge up to 90-100$ an hour.
If you have other skills like after effects, photoshop and videography you can make more.
If you get a full-time editing job you can make from 65k-120k a year.
It you want to make more money, you have to learn more skills, like motion graphic. Add this part to the video, it will make your video better.
The best way is when you editing video and become popular in this industry. You can open your own company to make documentary or shoot promotional video for some company
Hope this can help you.