Continue AFK farming but poke a bit. Being so passive until now your opponent will be vastly underestimating you. They will often go all in trying to kill you. you should win most all in fights It will be a long fight so by the time they realize they aren't going to win they will have over committed and if you played right you should be able to get a kill. But that doesn't matter. What matters if you farming so pat yourself on the back and keep farming and pushing. Don't worry about ganks, I don't even recommend buying wards. When you get ganked knock them up and silence nad casually walk back to your tower spamming your laugh the whole time.