You now know the pieces. This lecture is about assembling them into something a team runs every day, because a suite is more than a pile of tests.
Decide what goes in it.
Not everything. A regression suite protects the journeys that cost money when they break. For a typical product that is: sign in, the main create-and-view flow, checkout or whatever completes the transaction, and the permissions that keep users out of each other's data.
Anything you can check more cheaply elsewhere should be checked elsewhere. Field validation logic, currency formatting, date maths: those are unit tests, and putting them in the browser suite makes it slow without making it safer.