Hi Kheckel :)
I assume by 'friend' you mean someone from your Chess.com friends list? So long as you and your friend are both in Live chess at the same time, select the "Friends" tab, select the "Play" option next to your friend's name and then select your chosen time controls, etc. A challenge will be sent to your friend who can accept and play a live game with you.
Is there a way you can play live chess with a friend? Not the On-Line game.