First time buying a bicycle for dirt road/pavement on a budget.

I'm wanting to buy a bicycle but I don't know enough about the market to know what is or isn't a good deal. I live on a dirt road that's about a mile and a half long before it hits any pavement, and then another mile or so until it reaches a gas station. I sometimes want to go there to get a drink or a snack, but it doesn't seem worth it to drive my car and walking takes too long. There is also a nice biking trail a few miles down and I might like getting into bicycling for the exercise and fun. I'm looking for a bike that'll do well on the dirt road - which has only minimal spots with light sugar sand - and will also feel nice on pavement. I'm on kind of a tight budget - $200 or less would be ideal. Any information would be greatly appreciated. Thanks! :)