I was given an old macbook, but when I tried signed into iCloud to get my calendar

Question

I was given an old macbook  which I've slowly been making my own, however, when I tried signed into iCloud to get my calendar and contacts onto said macbook, all of the previous owner's data merged with mine. I lost all my phone numbers, gained all of his on both macbook & ipad and now I'm not entirely sure what to do. if I sign out of iCloud all his data disappears, my email address remains, but all phone numbers are lost. If I sign into iCloud, he apperas on my Ipad gain. I am confused and need help. Anyone..? Thanks in advance
Longlip

Answer 1

You can see if they might still be on your Mac, but just not in view by opening Contacts (Address Book), go to View>Groups to display your groups on the left sidebar, then seeing if they might be under On My Mac.
If they aren't, and they aren't in your iCloud account or any of your devices, you may be able to restore them from your iCloud backup (if you have one).  Doing this is a bit tricky as you have to pull the internet connection to interrupt the restore process after the contacts are restored, then turn off iCloud contact syncing on the device, then reconnect the internet and finish the restore, delete the existing contacts from iCloud then turn on contacts syncing on the device again.  Otherwise, when the restore process completes and your device reconnects to iCloud, the contacts in iCloud will overwrite the restored contacts on the device.  The process for doing this is outlined in this user tip if you want to try it: https://discussions.apple.com/docs/DOC-4841.
If they are still on your Mac under On My Mac, you can select the contacts and save them to a vCard file by going to File>Export>Export vCard.  Then email this file to yourself, open it on your iPad and tap the attachment to import them to iCloud.