If you’re an Uber driver, you’re technically an independent contractor with Uber, not an employee. This means that Uber isn’t obligated to withhold your taxes as it does for employees. Since you’re the owner of your own business, you’re responsible for calculating how much you owe in taxes from your Uber income.
Since W-2s are used to report income when you’re an employee, you won’t receive this type of form. Instead you’ll receive a 1099-K, and potentially a 1099-MISC as well. You will receive either of the two forms from Uber before January 31st, 2020.