Total newbie - SQL/installation question

Hi,
I'm going through the installation, but this is the first time I've ever tried anything like this so may be missing something out! I have uploaded the files through filezilla and have created a SQL database. I am totally lost on the next steps:
The user that was just created needs to be added to the database, along with enabling all of the necessary permissions
and
You should open up a web browser and enter in the web address of where they uploaded OpenCart.

Where/how do I add the user to the database, and what exactly is the web address where OpenCart was uploaded - www.randomwebsite.com/opencart - for example?

a database user is created and added to the database in your hosting panel.
most hosting panels do have a database wizard, it guides you through the steps of database creation, create user, and add all permissions.

make sure you make note of database name username and password.

opencart should be uploaded in the root of your site, check hosting documentation where that is as it differs on how the server is build.

normally you use the registerd domain name as that is where you want your shop to apear, if done correect, a installer will show, just follow the steps