Enjoy your rite of passage!
A first roadtrip can be thrilling.
It's pretty tough for us to give you an estimate of your travel costs. Too many variables. How you intend to eat, what activities you intend to do, the gas consumption of the vehicle you're driving, and lodging will all factor into it. This post will give you some tips on how to go about figuring out your expenses and creating your budget. And this post will give you some tips about how to keep food costs down.
Here's some other tips that might help you sort through what you want to do and how best to do it. That article also contains some good information to work through with your parents in case they're having trepidation about your plans. And be sure to follow the link to the Roadtrip Compatablity Quiz in that article. It will also help make sure you are all in agreement about things and how to handle issues that might occur while on the road.
Two or three weeks is definitely long enough to do this trip in. The issue will be your budget. Work through the steps to get an idea of what you think you'll need. Feel free to come back here with your budget so we can advise you if it's realistic or not.
Camping is a great way to keep costs down. It will always be cheaper than motels.
Well, let us know how we can help you further. Happy planning!