Edit Audio codec

[Efficient_Good_5784]

As what @tmsrxzar said, you'll have to use MKVToolNix: https://mkvtoolnix.download/downloads.html
The mkvpropedit file will be installed in the same folder as where you install mkvtoolnix. You'll need to use the command line/command prompt to use it though.
If that's too complicated for you, mkvtoolnix also provides a GUI interface that will handle everything for you.

1) is there a way to remove the "Fre" from by second audio

Jellyfin will detect what the language flag is set in the file properties.
It inserted "Fre" in there based on that flag.
I think you may be able to remove this if you use mkvtoolnix to remove the flag (and have that file not be linked to a specific language).

2) I already ask in the most long time ago, is it possible to change the "Dolby Digital+" to "EAC-3 or DD+ or something chose" ? Dolby Digital+ is pretty long name and the esthetic behind that isn't clean like others Codecs like "AC3, AAC, DTS, DTS-HD" that are naturally see by Jellyfin. Ultimately something like that would be ideal "English - EAC-3 - Stereo - Default" 

Though I do want to point out that for track naming on Jellyfin, everything before the first "-" is the actual name. Anything after that is populated by Jellyfin itself.
So from your examples:

1. English - Dolby Digital+ - Stereo - Default
   
2. French - Dolby Digital+ - Fre - Stereo - Default
   

The most you could change would be this:

1. <Your Track Name Here> - Dolby Digital+ - Stereo - Default
   
2. <Your Track Name Here> - Dolby Digital+ - Fre - Stereo - Default
   

Basically, both your examples have just the language name as the filename.
If you want "Dolby Digital+" to display as "DD+", you'll have to modify the Jellyfin source code yourself, then build and run that custom Jellyfin server.

Also, it looks like both audio tracks are set to default. Jellyfin will display which track is set with the default flag.
You can also change this with mkvtoolnix too.