My contacts won’t sync from my iPhone to my iPad

1. Open Settings
2. [Your Name]
3. iCloud
4. Toggle Contacts

Ensure this is done on both devices, additionally ensure you have enough iCloud storage, if not follow this article to upgrade: https://support.apple.com/en-ca/HT201318

Cheers

Restart both devices, on the one with the contacts, is there a banner at the bottom saying anything with the words "sync", "uploading" or "iCloud"? if there are plug the device in and let it sit for a bit.

Navigate to Settings>Your Name>iCloud - Make sure Contacts is toggled on.

Do this for your iPhone and iPad