MobileMe and iCloud

MobileMe is very old.

Do you have @mac.com, @me.com or @icloud.com?

If you do then you have an iCloud account.

To sync your contacts & calendars make sure you use the same Apple ID & password

on all iOS devices (iPhone, iPad & iPod touch):

Settings > [your name] > iCloud > Contacts & Calendars: turn it ON here.

On your Mac:

> System Preferences... > iCloud > ticked Contacts & Calendars.

Did you also link to the contacts manager(s) (Gmail, Yahoo, Outlook, Exchange,...)

If you have duplicates, it's like because of that.

In the meantime, check you contacts by using your Mac's Safari with this link: https://www.icloud.com/#contacts

You're welcome.