Hello M0716,
Thank you for using Apple Support Communities.
It appears that you ar having an issue with the emoji keyboard not showing up. What do you see when you go to Settings > General > Keyboard > Keyboards? If you don't see emoji keyboard on the top section then tap "Add New Keyboard" and find emoji to add it back.
If you see the emoji keyboard in the top section, select "Edit" and remove the emoji keyboard, restart the iPhone and re-add it.
If you continue to have the issue, get back with us and we can see where to go from there.
Best regards.