To know if your Upwork profile is approved try to submit a proposal for any available job and see if there is any response from the system. If your account is not approved, you should get an error message telling you that you can only submit proposals when your account is fully approved
Your profile has been approved. You may start sending proposals. Please check out this thread to help you get started on Upwork and also these helpful blog articles to help you write winning proposals, improve your profile and tips on how to be successful on Upwork. Feel free to reach out if you need further assistance.