Giving tips is a little but harder when we don't know a lot about you. How tall are you? Ages of your family? What Types of coasters do you like?
As for me, usually my girlfriend and I spend $20 on food. I have a souvenir cup so drinks aren't a big factor in cost. Sometimes we snack on pretzels or ice cream.
So food and drinks - 30-40 dollars if we stay all day.
Rides: I ride them all, there is nothing too tall or fast for me. My girlfriend will ride everything as well and living 25 minutes away (in light traffic) I don't buy fast passes all the time.
If yo enjoy coasters as much as we do, I recommend The Beast, Diamondback, Firehawk and Flight of Fear. All are GREAT and different experiences.