I manage to get to step 4 of the General installation document. There, when i choose my password (or leave it default) i get the following message: "Failed to connect using the given credential "and its shows me a step3-like page which ask me if given information is correct? I use zoomla CMS and everything seems correct in that page but i still get that error.

Are you trying to install in on your localhost ?

If yes , please try using 127.0.0.1 as your host ,
if not we can install it for you , we will need your Cpanel / SSH details

i try to intall it on a web host ..What details do you need?

Your Cpanel or SSH or FTP login details and backend adminstration login details .