Not necessarily a scam in that they really are a third party gas supplier of PG&E, but I wasn't told about other fees associated with it and was rushed to just scroll through the contract and sign. They offered lower rates for gas but told me nothing about other fees. I looked at the contract right after he left and saw the other fees. I'm going to cancel on Monday before my right to cancel without any fees and penalties is gone.
(Guy about my age says he's taking a gap year at the university I'm going to right now. He came at like 5:48ish and while I was looking up my PG&E info to get the service agreement ID, he casually chats that he will finally be done for the day and off work at 6pm. Seemed friendly but inside I kind of felt rushed, since I never look at the second page of the PG&E mail, so felt bad about probably being the last customer he's going to be explaining for that will bring him over 6pm. On the contract page, I was just going to slowly scroll through it and planned to not hit submit until he's gone to really make sure of the details, but he said to scroll all the way down and hit next, and only left after I did so.)
Update: It's already Monday. I called and managed to cancel it without any fees. Lesson learned: I need to be either more wary of people coming up to my door, or keep it locked and act as if I'm not home. If it's really important, I'd probably get a mail or message from them either way.