After you've built your test suite—even if it's only a single test--the next step is to run your tests. You can run against a number of different browsers, schedule them to be run at times convenient for you, and preview what the testers will see before starting the job. These topics are covered in separate articles here in the Runs section.
Running a single test
Starting at your Tests dashboard, select the test you want to run. Click "Run test" in the upper right hand corner. Under "Override default browsers", select the browsers against which you want to test. Click on "Run 1 test". This will run the test in the chosen browsers.
You can optionally provide an arbitrary description for this run
Running multiple tests
Use the Result / Site / Tag filters on the right hand side of your Test dashboard to narrow down which tests you want to run. You can even run all of your tests by not applying any filter by clicking "Run Tests" and then choose "Run # Tests".