First you need to create account at DocuSign Account creation
After your account is created you can proceed to DocuSign initial setup
Once you have your DocuSign account set up go to Jira DocuSign plugin installation Installation
As final step perform basic Jira DocuSign setup Jira initial setup
Finally you can use your DocuSign to sign documents How to sign document
All of the above steps are shown as short videos at How-to articles