Cannot Install the client on OS X

Hello,

I’m OS X 10.11. I have installed Letsencrypt with:
git clone https://github.com/letsencrypt/letsencrypt
which went fine as far as I can tell.

Now I type this, as per instructions:
$ cd letsencrypt

Now I think I’m inside it, I type:
./letsencrypt-auto --help
and it says:
-bash: ./letsencrypt-auto: No such file or directory

I cannot proceed further, what am I doing wrong!?

Have you checked if you’re really in the letsencrypt directory? Is letsencrypt really installed?

How do I check that?