You will need to verify your email and then hire your freelancer. Once this is done you will be able to pay them.
If you set up an hourly contract every Monday you'll be invoiced for the previous week's hours based on your freelancers' Work Diaries. If you set a up a fixed price contract, once the freelancer has requested a payment request you will be able to release the funds.
I would also recommend checking out our resources here: Client Tutorial Videos and Client Webinar Getting the Most Out of Upwork. Thank you.
I checked and it seems that your email address is already verified. Could you please send me more information about your question so that I can check and assist you further?