Mitch DJ0QX will be a great help -- he has an awesome checklist which will take you through all the necessary steps.
High level, you need to check your homebase station first and make sure it is working, then confirm your "control" side is working.
(1) From your web browser, can you reach your homebase station? Can you login to the "radio side" Remoterig box from the public internet?
If not, did you leave remote administration of your Wireless router turn on (available to the public internet?) Can you reach it?
If not, can you check status on your DDNS, and is it working? (If you are using RemoteRig DDNS:
http://ddns.remoterig.com/status/index.php)
If all the above is okay:
(2) Can you login to your "control side" Remoterig box, and does it "see" the public internet? Check that you are using DHCP on it, and follow the other steps suggested on Mitch's checklist.
Hope this helps--
Jim N6TDC