You have forgotten your Mobileme user name and password. Is there a way to retrieve this information? You can use Apple's password retrieval utility.
You will need to enter in your Apple ID. Also, you can click on "Forgot your Apple ID?" link to try to retrieve your Apple ID. You will need to enter in your first name, last name, and current email address.
You can either change or reset your Apple ID password. Mobileme is precursor to Apple iCloud. Users had a choice whether or not to transition to iCloud.
Your Mobileme account is still active according to this Can I use my MobileMe account for Apple services without moving to iCloud Apple support article updated on January twenty seven two thousand fifteen.