> Is there a way to have emacs with custom shortcuts as a ready package where I can modify those shortcuts before digging in with all the rest.
I've got a very custom Emacs keybindings/shortcuts setup but... Sadly it requires some hackery: basically there's the whole major/minor modes shenanigan where one mode's shortcut can take precedence over the other(s). And if you want to define your own shortcuts which take precedence, all the time, over everything else, you need to dig a bit deep. And then even deeper because invariably there's this or that minor mode you'll want to use where after all you won't want your own shortcut but that one of the mode.
> I am looking for the way to set those by myself but it seems I need to learn a lot before I can do it
Sadly this is true. I've got I'd say about 100 lines of code related only to keybindings. Now, once set up, it's pure bliss. For example I've got mod+{i,j,k,l} to move the cursor around, anywhere (text, menus, anything). It makes even more sense than vim's hjkl (ijkl mimics the cursor arrow keys layout, which is more natural and ijkl is easier to type than hjkl too).
> ... and thus it blocks me from moving forward with exploring Emacs deeper.
I can understand that. I'd say the easiest would be to define your own minor mode as explained here:
https://stackoverflow.com/questions/683425/globally-override...
This should get you started: if you do it like in the answer and make sure they always take precedence you should be good to go and can deal with the gory details later on.