You can get sleeping pills on Tuesday. When you try to get some sleep, the phone should ring. Pick it up, talk to Alex P, he'll tell you to go grab some sleeping pills at the store.
For time travel knowledge, you can get them in 2 ways.
> If you're going for an A, try to study for the mathematics test, and study the stuff at the end of the book as well. Your character will learn Time Travel by studying the stuff not on the test.
> If you're aiming for an F, Study for the mathematics test, but choose the option that "you're too tired to continue" When you get to the actual scene where you're taking the test, choose "give up..." and your character will not only keep his sanity, but grasp the concept of Time Travel as he flees from the math room in terror.