I would play more but i only play in friends-crew only lobbies.. too many hackers. I seem to run into at least 1 in every lobby using it to troll and greif people
You can start a Crew only session from your singleplayer.
"You have to do it from the single player pause menu. Go to the Online tab, select the bottom option to go onto GTA Online and then the options for crew/friends only sessions and/or solo sessions should pop up"