Hello Alonzo,
Configuring of firewall rules in Compute Engine are straightforward steps which are described in this article. I am not expert of TeamSpeak so I might not be able to help you with configuration issue of this software, however I found this link that listed all default ports and protocols used by TeamSpeak 3 Server. Note that in addition to ports and protocols, both inbound (ingress) and outbound (egress) direction of firewall rules should match to the requirements specified in the article.
That being said, I'd recommend posting this question on serverfault.com or TeamSpeak community forum where you will have access to experts of TeamSpeak and it would be quicker to get help on configuring of the software.
Also, please feel free to visit this doc for GCP community support overview.
Sincerely,