Hello Frxxnzy,
In order to create a 2v2 private match, you'll need the Fireteam leader to open the Director, select The Crucible, then select the Private Match node. This will then allow the Fireteam leader to select their desired match settings under the "Game Options" menu. Players who wish to join an existing Private Match must join the Fireteam of another player who is currently in a Private Match lobby.
For more information on Private Matches and how to set them up, please refer to our help site at:
https://help.bungie.net/hc/en-us/articles/360049200051-Destiny-2-Private-Matches-Guide
Hopefully this information helps, and if have any more questions please don't hesitate to reach out.
All the best