Begginings are always the hardest part. You start with only a few books in the middle of wasteland. If you don't know how this pack works, it will be much harder for you to progress.
When you log-in for the first time, you probably land your eyes on a thirst bar which is right above hunger bar. You can refill it by drinking some liquids but when you drink anything that is not clean you get poisoned. I suggest getting a wooden cup, wooden barrel and waiting for rain ASAP. Filling it and clean it with a filter should be your next top priority.
Next thing you want to craft that differs from vanilla gameplay are 4 tables on which you can create and assemble tool parts (stencil table, part builder, tool station and crafting station/table).
Another thing you need to know is that parts can't be created from any material (can be seen while holding SHIFT). First tools are best made of flint (also craftable; use NEI for recipes).
There are obviously other rules and mechanics I haven't mentioned but if you are stuck with something and mod wiki isn't helpful then feel free to contact me. Good luck with your journey...