Apex domains cannot have CNAME records.
Question and response
Question
dig fistthingsfirst.com. NS
Answer
fistthingsfirst.com. 5 NS ns-1380.awsdns-44.org.
fistthingsfirst.com. 5 NS ns-131.awsdns-16.com.
fistthingsfirst.com. 5 NS ns-26.awsdns-03.com.
fistthingsfirst.com. 5 NS ns-28.awsdns-03.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0