Sandy,
Welcome to the forum - this has been a great place for me to learn how to use the excal and gt, and I hope you get as much out of it as I have so far.
As for the Excal, all I can say is "use it, use it, use it, and then use it some more". I'm still relatively new to using the Excal and the GT, but BC in NJ is right = go slow, don't try to cover large areas all at once - pick an area to MD with it, and then take as much time as it takes to cover that area as completely as you can. Then pick another area and do the same thing. If you are striking out in one area, there is always the "grass is greener over there" thought.
I keep a 35mm film container in my pocket with a silver dime, a copper penny, a zinc penny, a nickle, some foil, a bottle cap, a pull tab and a gold ring in it. When my ears can't tell the difference between things any more, or I start getting confused about what I'm hearing; I lay out something like the pull tab, foil and the gold ring and listen for the differences. Sometimes I will do that with a different combination of what's in the film container, but I find it helpful. Other times, give your ears a break for 10 or 20 minutes, then get back at it, and it will make all the difference in the world as to what you are understanding that the machine is telling you.
I still listen to Basic Ear Training for the Excalibur on a regular basis, and it helps a lot to learn the sounds of the machine. You still have to do your own homework in terms of figuring out where the good stuff is; that is a matter of studying people and their habits as well as beach movement/sand movement/erosion. There are some good books out there too. I like the Clive Clynic books and the Gary Drayton book. Clive is more technical, methodical in his explanations, but the information is there. Gary is a little easier reading in some ways, and might be a better starting point. These are just my opinions - Both are great sources of information, one isn't better than the other.
Hope this helps, and if you have questions; post them on the forum, people here are real helpful.
HH and cover your holes,