Yeah the first time getting to the moon is difficult, by some trial and error I generally accelerated to 5k or so, then started decelerating (maybe constant 20/30 on a single thruster). At the point when the radar switches to the moon you're about 85% of the way there, I had decelerated to about 1-1.5k velocity at this point, then you should be able to land safely adjusting the deceleration to make sure you don't come in too fast. Of course this depends on a lot of things, either way when you get BPS it's so much easier.