I don't think you can handbrake is a video converter not an editor. I would look at hitfilm express or the blackmagics free one. I can't think of the name of it it's not davinchi as that is the color grader and more starts with a F

I have used the output fro Hitfilm through handbrake when I didn't want to fool with compression settings but hitfilm has all the editing titling sound tools. Express is free