How to restore my contacts

If you are using iCloud, make sure you have contacts set to sync.

Change your iCloud feature settings [iOS and Mac] - Change which apps sync and store data with iCloud - Apple Support

If you accidentally deleted your calendars, reminders, bookmarks, or contacts from iCloud, read this support article --> If you accidentally deleted your contacts, calendars, or bookmarks from iCloud - Apple Support

Noles7176 wrote:

How to restore my contacts

If you were syncing contacts look here Use iCloud.com to restore and recover iCloud information - Apple Support

IF you were syncing to your mail account renable contacts in message settings or ask your mail provider how to restore contacts.