Open terminal and log on as the user created in the install:

su - [frappe-user]

Enter the password then:

cd ~/frappe-bench
bench start

You will see a bunch of text in the terminal - look for the following text.

Running on

Right click and open link. This will open your project in your browser.
Log in and you will be at the desk (backend) of your project - to see the website go to the top right of the screen you will see "settings" - click on this then "view website"

To quit go back to the terminal and Ctrl+C