Don't have experience with your particular boat, but I can sympathize.
All the comments so far are good, especially about shifting into neutral to disable prop walk. One comment about prop walk, though... on most boats (all boats with right-handed props), prop walk is to starboard in forward and port in reverse (i.e. the stern is pushed in those directions). If you forget, curl the fingers of your right hand and point your thumb in the direction the motor is pushing your boat. Your fingers curl in the direction the prop is turning.
The next thing to realize is that, depending on what direction the wind is coming from, you might want to back out in one direction or the other. In my boat, there's a very strong tendency for the bow to blow off downwind. Since I need to depart to starboard, a wind from port is very nice since I can just back out straight and quick and the wind and prop walk will work together and make for a nice tight turn, after which I'll motor ahead.
On the other hand, sometimes the wind is coming from starboard. In this case I'll back to starboard all the way out into the marina's fairway, then motor ahead. It's tricky since i'm fighting the prop walk in this case.
Learn to work with the various forces acting on your boat, instead of against them, and you'll have a much easier time of it.
1972 Catalina 27