There are a few ways to log in to your account. You can either go to Uber's website at www.Uber.com and select the Sign In option in the top right hand corner. This will take you to a page where you have an option to sign in as a Driver or a Rider. Select the Driver Sign In option and enter your pertinent information. You will now be in your Driver account.
You can also go directly to https://login.uber.com/login and log in with the pertinent information.
If you are wanting to log in on your phone, make sure you have downloaded the Uber DRIVER app. This is a maroon colored app and different than the regular Uber rider app. Once downloaded, enter your log in information. You are now in your account.