To set a static IP address use:
'nmcli connection add type ethernet con-name connection-name ifname interface-name ip4 address gw4 address
EX: nmcli con add type ethernet con-name test-lab ifname ens9 ip4 10.10.10.10/24 gw4 10.10.10.254
To set the DNS address use:
EX: nmcli con mod test-lab ipv4.dns "18.104.22.168 22.214.171.124"
In addition to Bob's answer, you can also directly edit the interface script at /etc/sysconfig/network-scripts/ -- Just make sure you know what you're doing if you modify it this way. You'll need to know, for instance, that IPADDR=[address] is the way you assign the IP within the file itself, in addition to other necessary values like the default gateway that correspond to those in the nmcli command Bob wrote out. You would set the BOOTPROTO= line to 'static'