Need to recharge my Fenix 7 every day. How to avoid that ?

The easiest way to do this is to change to settings that don't consume batteries like this.
I don't know what other advice you were expecting here.

Ahahah!  I wish you could be more explicit in determining which elements of the settings needed to be changed.  It is like saying,"please check if the TV is plugged in the electricity outlet" when I ask say that I cannot turn my TV on.  In following your advice, which means set the battery option to 10 days savings, I lost my Watch face and only got the time display on black background.  There must be a way to disactivate the GPS function which is pernanently tracking my watch even when I dont need that to happen, and keep my watch face active.

Ahahah!  I wish you could be more explicit in determining which elements of the settings needed to be changed.  It is like saying,"please check if the TV is plugged in the electricity outlet" when I ask say that I cannot turn my TV on.  In following your advice, which means set the battery option to 10 days savings, I lost my Watch face and only got the time display on black background.  There must be a way to disactivate the GPS function which is pernanently tracking my watch even when I dont need that to happen, and keep my watch face active.

4392559 said:

There must be a way to disactivate the GPS function which is pernanently tracking my watch even when I dont need that to happen,

It isn't. What I suggest you do is reset the watch - Use the Reset Default Settings option. Then read the manual and start from the beginning as if a new watch.

will I loose all the data (sleep records and so on) when doing so ?  Or is it saved in a Garmin cloud ?

You shouldn't do. As you are only resetting the default settings, those that you changed when you set up the watch.

OK. Thanks for your suggestion