I would like to edit my videos. Do you have any advice?
There are plenty of software packages available that you can use to edit your videos yourself. Some are free and some must be purchased. Most allow you to cut and trim your video, insert images, overlay text, as well as adding music and sound effects.
For starters we'd certainly recommend the following:
Windows Movie Maker - for Windows computers.
iMovie - for OSX (Mac computers).
Also, for Mac users, there are a large number of packages available for download on the Mac App Store.
If you are looking for something more advanced consider: