Rachael, - It'll work if you have the skills, qualifications and expertise that THOUSANDS of the contractors (worldwide) have on here. You're competing with professionals who have had careers consisting of years of experience. There are so many contractors on here, joining every day and added to that are all the contractors who have been brought over from the freelancing site Elance (which has been acquired by Upwork) that Upwork is limiting any more from joining at the moment. That's how saturated this site has become.
If you can rise above all of that, then yes, it can work.
Before you start bidding, working and getting paid on Upwork, you will have to complete you profile according to the guidelines and have it approved. Please, refer to the notification the team sent you earlier today for more information.