Whether you work primarily on a Mac or PC, here are several cost-free options to consider.
Plenty of tools to improve video and audio quality.
Limited advanced features available.

Terrence Phiri / Pixabay
Output controls are lacking.
iMovie is free for macOS users.
It’s easy for beginners to start using.

Wikimedia Commons
you’re able to even start editing on your iPhone or iPad and then finish on your Mac.
User-friendly with a classic Microsoft feel.
Great for beginning video editors.

Wikimedia Commons
Very limited without the Pro version.
Free version supports HD only.
Movie Maker was Windows' pre-installed free video editing software.

The interface is user-friendly, but the free version of the app faces some limitations.
you’re free to only save projects in HD and sharing is possible only with the Pro version.
It’s open source.

The utility has multiple layers of setup.
you’re free to download it free for Windows, Mac, and Linux systems.
Export Videos to YouTube on Windows and Mac: VideoPad
Supports a range of video formats.

Wikimedia Commons
Easy to install and use.
Another video editing software program for both Windows and Mac is VideoPad from NCH Software.
Features you won’t find elsewhere.
Exports to a variety of file formats.
Includes an optional screen recorder.
Some video lag with the free version.
VSDC is a full-featured free video editing tool that you’ve got the option to install on Windows.
There’s even a wizard you could run to make things easier.
Plus, as any good video editor should, VSDC can export videos to a variety of file formats.