Congratulations on taking a BIG step toward better health.
I can't answer your questions in the proper way. I can only tell you what I did and I jumped right in doing my first Liver Flush with no prep work. I didn't use Andreas' method, but I hear it is very good. I used Dr. Clark's Liver Flush and have completed many flushes and never had any problem.
After my first liver flush, I learned a little more and did a Colon Cleanse using Bentonite clay and it was very successful.
I looked for a free Andreas book download and all I found were several utube videos. Check on that website and something there may help.
The important thing is not to overload you mind. There is so much to learn and it is so easy to absorb too much information and retain very little.