There are two options really based on what you might have access to in your DocuSign plan

1) "Sign a document" under NEW, this basically allows you to upload a document and then drop your signature tag along with other fields as needed, to the appropriate locations.

2) If you do not have "Sign a Document", just use "Send an Envelope", upload the document, add yourself as the Recipient (needs to sign), change email subject and body, click Next, drop Signature Tag and other fields and Send. Since you are logged into DocuSign it should prompt you to just sign the document at this time or you can use the email link you get.