MP4 video editor recommendations ?

Yesterday I tried out an old Gopro HD Hero (2010-2011).
All of the runs recorded fine, although a little shaky due to the experiemntal mounting.

I'm looking for suggestions for a video editor that can do the following:
1. Clip and save just the run, or even portions of the run.
2. Side by side comparison or the runs or portions of the runs.
3. Possibly saves in a more compact or reduced resolution to make it easier to share direct or maybe even upload to a serice or my webhost.

Operating system:
Windows 7 Professional.
Windows XP (if it works with XP, great. Not a requirement.
XP came with Windows Movie Maker (2002) but it can't read MP4 files.

Program requirement:
Must be stand alone capable.