Cut engine to zero, Warp in time, till you hit the yellow bit, where it will draw a new line. Turn around 180degrees and throttle up, the new line wil slowly come in and encircle the mun, if you want to orbit leave it in a circle, I you want to land keep it throttle up, until the lines intersect the moon, throttle down to zero %, when down to about 50000m altitude throttle up and slow your decent.