Can I add metadata to a Video file?

Movie metadata is a mess and a moving target.

But I have used exiftool to add or modify dates and locations, and in a limited manner also titles, captions, keywords, device make & model in .mp4, .m4v and mov.

I have tested and used metadata tags that QuickTime Player and Photos.app support, such as:

QuickTime:CreateDate

Keys:CreationDate

Keys:GPSCoordinates

Keys:DisplayName

Keys:Title

Keys:Description

Keys:Author

Keys:Keywords

Keys:Make

Keys:Model

Keys:Software

Movie dates and Photos.app - Apple Community

https://exiftool.org/forum/index.php?topic=12176

Metadata support for video is very patchy and, given that most of the suffixes you mention there are actually containers for any of a variety of codecs, the whole video/metadata situation is not good. In many cases there is simply no space in the file for this kind of supporting data. Some newer cameras will manage metadata, but it's an evolving situation. Most folks use the filename to preserve the details, as that, at least, is reliable.

AFAIK .avi does not support much metadata so I'd convert to .mp4 and archive the original .avi.

I am usually quite cautious messing with original raw metadata (.cr2, .cr3, .dng) so I routinely just rename them as YYYY-MMDD-hhmm-ss.* like I do with other image and movies with GraphicConverter or exiftool based on their metadata datetime. But occasionally I have added GPS, ratings, captions and keywords also to such raw files with no ill effects (I dislike clutter from sidecar .xmp files). exiftool is very safe in this respect and it should refuse to touch unsupported formats (just the other day exiftool author was asked to add support for Panasonic Lumix GH6 .rw2 files).

https://exiftool.org/forum/index.php?topic=13861.0

You can edit the exif on a NEF with Exiftool.

What do you use to process your Raws now? Most raw processors will edit metadata too.