SSH problem with creation of public/private rss key pair

Why, after the creation of public/private rss key pair, the terminal told me that i’ve to save the key?
Where i have to save the key? Because the following step would be just this:
log on the remote host and create the .ssh directory in your profile
ssh username@server4.dicca.unige.it
mkdir .ssh
exit

Why after put mkdir on the terminal the answer is “il file esiste gia”?

And then why it works in this way??

ok, now it works

Then with VCS, what user i’ve to put?
And the email? I enter mine?

Where is the mistake?

on a terminal log onto the remote host then try this:

group

then try this:

ls -l /d1/users

then this:

ls -l '/d1/users/PERT repository Git'

and filnally this:

ls -l '/d1/users/PERT repository Git/fc.git'

then post here the results

i’ve put the same passages of the last time.
Now it works why?
Then, in the following line where i’ve to put ( Git/nome_repository.git" ) i write Git/fc.git but the terminal replies in this way, why?