I use a fresh Mageia 6 with gnome-shell and 64bit. I have two accounts (or users), is there a way to set each account with its own language for example my account is in English and the other account would be in French.
Yes, you can set this up from the settings. Open the menu at the top right of the screen, click on the settings icon (the tools in the lower left of the menu), click on “Region & Language”, and choose your language in the top field. This setting is stored per user.