This achievement is fairly straightforward and can pretty much be boosted with a few friends or just one friend. The unlock requirements on some of Fallout 76's achievements have been known to be somewhat sketchy but this is as follows...
Start a world/join a random world. Have that friend join the game too. Have them invite you to a team through the social menu and then just hang out for a minute. Then either leave the team or leave the game entirely (essentially disbanding the team), load into a new world, and rinse-and-repeat.
Like I said, sometimes unlock requirements can be sketchy, as far as I am aware I did this just playing with people I knew as I hardly ever played F76 with strangers. In the event it doesn't work with a few buddies, asking around on the server using the social menu with the emphasis you're boosting for an achievement should help... some people, more often than not, will help either for free or for a few caps.
Take care out in the Wasteland folks!
UPDATE: Here's a slight addition from the comments user "oxHARMONxo" mentioned. As this achievement could be bugged depending on the type of invite used. They stated "I remember reading someone said they had well over 20 teams, but it only unlocked after a face to face invite. Just tried a face to face invite after dozens of teams and it unlocked first try..."
So if you're in doubt and can't get the invite to pop through the in-game social menu, try inviting them through any other means necessary such as through Xbox Live or directly face-to-face in game when hovering your cursor over them like you would to trade.