1. concrete5 needs to be installed onto a server, not onto your local (client) computer. If you can access the editing mode of a concrete5 installation, it sounds like it's already been installed.

2. You probably don't need to use ftp at all, if concrete5 has already been installed. You can upload images and other files that you want concrete5 to display from within concrete5 itself. If you DO want to use ftp, set it up to connect to your host as normally would. concrete5 is just a bunch of files on your host (plus a database).

3. No! :)

Thank you so much for your answers and help.

This is the current situation with my client, they have already a site in concrete5 with a very outdated version, Concrete 5.4.2.2 they need to update the design, so I am looking the possibility of instead of updating concrete5, start from zero in a actual version of concrete 5 since this is a not complicate site.

Now the question is how do I install a current version of concrete5 in the hosting company that they have without eliminating the existing file while working in the new one?

Your approach sounds ideal.

Before doing anything, make sure you've got a full back-up of the current site (files and database).

When installing a new version of concrete5, install it into a different subdirectory and give it a different database name. Your two installations should then be totally independent of each other.

When you're happy with the new site, you can move it into a different directory (eg, so it's the same as your current site). There are some tricks to doing this, but it's quite possible.

Concrete5 is one of the premier go-to web publishing platforms available today.
Getting started with Concrete5 is really quick and easy, and many hosting platforms now offer one-click installs. If you have SimpleScripts, Softaculous, Installatron, or even Plesk’s Applications Installer, you can simply find Concrete5, install and go.