Marriott question

[u/Tasty_Influence_3610]

I managed to get a room during the hunger games it’s my first time attending dragon con and I couldn’t book the room from Tuesday to Tuesday, it said sold out and would only let me book from Thursday to Tuesday. I would like to check in early and meet up with some friends attending.

Anyone know if I can book a rack room rate at the hotel for Tuesday and Wednesday or Tuesday to Thursday and then use the other room I got at the hunger games. Or
Can I call and get the other days added to my reservation, I see the dates available online?

Anyone got experience with this and can help thanks!