Create a directory

mkdir /teamspeak

and a non-root user

adduser teamspeak --system --home /teamspeak --disabled-login

Get the server package downloadlink from either the website or directly from the fileserver

https://www.teamspeak.com/de/downloads/#server
https://files.teamspeak-services.com/releases/server/

Change to your directory and download the package

cd /teamspeak
wget URL

Unpack

tar -xjf PACKAGE

Change the owner of the files to your user

 chown -R teamspeak /teamspeak/ 

If you feel the need to change ports or add a proxy, you can create an .ini file and edit it

Change to your non-root user and execute the following in your teamspeak directory

su teamspeak -s /bin/sh 
./ts3server createinifile=1

You can also create a white- and blacklist to prevent users from joining

The server doesnt start and the log shows the following error

failed to register local accounting service: File exists

Reason:
A file was created by root and cant be used by your non-root user

Fix:
Check for a cryptic file in /dev/shm/

#ls -al /dev/shm/
total 39228
drwxrwxrwt  2 root      root        1800 Dez  5 11:41 .
drwxr-xr-x 17 root      root        3640 Nov 13 06:47 ..
-rw-r--r--  1 root      root         128 Dez  5 11:41 7gbhujb54g8z9hu43jre8

rm /dev/shm/7gbhujb54g8z9hu43jre8

If you start teamspeak now, the file will be created with the correct user

ls -al /dev/shm/        total 39228
drwxrwxrwt  2 root      root         1800 Dez  5 12:10 .
drwxr-xr-x 17 root      root         3640 Nov 13 06:47 ..
-rw-r--r--  1 teamspeak teamspeak     128 Dez  5 12:10 7gbhujb54g8z9hu43jre8

https://forum.teamspeak.com/threads/93623-Instance-check-error-failed-to-register-local-accounting-service-on-Linux/page8