The most straight forward option is to creat your own database for the xoops installtion. This way, you already have the name and password required.

Another option, if you do not have access to phpmyadmin to create your own, is to request the host administrators to create a database for you.

Remember ... you databasename may be prefixed by your user name. So you create/request a name of 'xoopsiste' but the full name is mysuername_xoopsite This is what needs to be inputted in the xoops setup.