As long as you have a valid email address then you can use this to sign up to the Go+ reward programme on the Shell Go+ at www.goplus.shell.com.
If you don't have a smartphone you can request a Shell Go+ loyalty card to be issued to you by requesting one from your new online Go+ account.
You'll need your plastic Go+ card with you each time you visit a Shell Service Station to claim your rewards and participate in the programme.
Once you have an online Go+ account and providing you are already a Shell Energy customer you can then link your two accounts together to get your fuel saving. Follow this link for further help.