My suggestion would be to start with the LORT contract. There are a lot of theatres that use it, or have an LOA ("Letter of Agreement") to it, meaning, they use it as a base and then make adjustments/concessions from there. The likelyhood that just out of college you'll be working on a show under a production contract is not high, but a gig as a PA at a LORT theatre is quite possible.
Don't stress about knowing all the rules right now. As you read more on this website, you'll see that there are SM's here who've been Equity for years who need clarifications on rules. Read the rulebook to become familiar but be forwarned, it is quite dry (it's a contract after all).
The best way to learn a contract is to work under it; even as a non-Eq ASM or a PA, you can pay attention to how the rules are used and which rules are really important for an SM to know (you really don't need to know ALL of them off the top of your head, just know that they exist).