Help a newbie at Black Crusade

i want to learn more about Black Crusade before the end of the month since i have a friend who is willing to allow me to join a group so i would like to do a test game and learn as much as i can so im not yelled at from the GM which is a friend of mine anyone willing to teach a noob at Black Crusade.....EXTRA INFO: i have played Deathwatch, Rouge trader and a bit of Dark Heracy...so i do know the gerneral basics but from what someone said this game's balance is set lower than these games i have played

if you have already played deathwatch, RT and Dark heresy. you are good to go. the differences between them will not make your gm yell at you. unless he yells a lot.

I'm still trying to find a game of RT, deathwatch or DH on here. Do you guys know of any games running on roll20?