I just got a job a little closer to home and want to start biking to work! It will be about 12 miles each way, mostly pavement with some dirt and gravel. I want to get a bike I can also ride in the woods. I was told a good bike to get would be a mountain bike with 29er tires. I'm looking for a budget friendly bike as I don't want to spend too much on my first bike. Any advice or suggestions?