Have you spent any time at all searching this website for the answers to the questions you have? There is a search icon up ^^^ there somewhere and if you click it you can search by forum, or click the gear icon for advanced search features.
I can guarantee most of them have been answered.
Coming on here like "tell me what to expect" is not going to be taken well from the people who have put alot of time and effort into posting content on here:
Preperation for traveling
Check out that link and read the posts in there, then, if you really feel like you can get prepared, go to the "Travel Stories" section, read some of those. Especially the ones that talk about how dangerous train hopping can be.
Then go to the "Train Hopping" forum, and read every thread that is relevant to where you are going.
All the info is on here, and if you are not willing to have the patience to read it before asking members to retype it, you are probably not going to have the patience for hopping trains.
Welcome to StP.