In you don't know some of basic details of your hosting account, such as it's username, IP address, physical location, etc., follow these steps:
1 - Access your Hosting Panel
Follow instruccions of How to access your Hosting Panel to access your Hosting Panel.
2 - Look at the left column
Once you are in the Hosting Panel, just look at the left column, most of the info you may need is there.
And the password?
The only detail not present in the left column is the hosting account's main password, which you can define following How to change hosting account main password guide.