You already have a client account on Upwork. To select your client account, please click the account drop-down menu at the top right and choose your client account as on the pictures below.
Afterwards, please go through this Help Article and find out how to make an offer and hire a Freelancer. You can post a job, verify your payment method, review proposals you receive, send an offer and hire a freelancer to complete this work for you, and process the payment as explained here. I'd also strongly recommend you to review the client resources we shared here. Let us know if you have any questions or need further assistance.