How do I prep for land nav at IBOLC At Home?

Join an Orienteering Club and get outside and try to find all the points. Time in the field with a compass and map works wonders.
I'm not a fan of dead reckoning, but there are places on Benning where that is the only option. Work out your pace count over varied terrain and make a pace cord. Check your count at night, it won't be the same.
Practice, Practice, Practice.

You should try getting out to an outdoor location with a map. To be successful you need to be able to terrain associate. You should also work on your draft. You could literally go out to anywhere in the woods and do this. You can just plot two points a few hundred meters away and then use a compass to calculate what you have to walk. Without looking at the point you were walking to you need to dead reckon. When you walk the distance you are supposed to you will notice that you will be either to the left or to the right of where you want to go. This is your natural drift. If you can learn to negate that you will be able to walk a true azimuth. Your drift is typically what gets most people lost.

I have done the same course in OCS. I used a map, compass, and pace count. I used terrain features, maps, and pace count to guide me. However, I will say when I went on the nav course I had more experience than you. What is your experience with land nav training? I don't want to corrupt you but when I went on the land nav course the effing Infantry 2LTs were moving in squad size elements looking for points, they even had flashlights for the night portion. What a bunch of effing cheaters.