Hi Roberto,
You should check out the developers forum, which is all about running CommCareHQ yourself, there's more information on this sort of thing there.
CommCareHQ now only supports Python 3 (we're on 3.6, currently). Here's the forum thread on the subject, which has some useful links. Though if you're setting up a new environment, it should be easier, since you don't need to migrate an existing one over.
It does look like the commcare cloud documentation still contains references to Python 2. I'll see that that gets updated. Have you tried following the steps described in the changelog for moving to Python 3? https://dimagi.github.io/commcare-cloud/changelog/0023-upgrade-to-python-3.html