Cryptography

[AQWThunder]

Here's something you could put your teeth in, it's an easier version of cipher I've had in my head for the better part of at least five years.
I'll just drop a hint, which route would you take if you only could take one?
Go.


Don't mind the big black boxes, I just fucked up because of fuck.

I have no clue whatsoever on how to solve this. Where did you learn cryptography from Mr. Zodiac Killer?