As long as you are the administrator of the account, you can renew your subscription by going to your account summary page and clicking "Purchase/Renew Licenses". Get to account summary page by logging in and clicking your email in the upper right corner of this website. You may also click here to go straight to the purchase/renew page.
Dassault Systems makes a CAD program called DraftSight which can be downloaded for free. There is also a professional version you can purchased directly for $149. We have found this to be one of the more intuitive CAD programs on the market, and really the best value out there!