Virmana

i'm a huge noob and youtube tuts don't cut it for me. I want to head to the mun. I see people fidgeting around with these maneuver nodes while in orbit(as am i), what i usually do is keep my thrust going until my apoapsis is within range of the mun, then what? i think this isn't enough, i need to face a particular direction and use whatever fuel i have left to properly arrive and i think maneuver nodes are for this reason. Thanks i'm an idiot.