u/Formal-egg-1899

So every summer me and my friends bike around 30 miles and I bike often on my own. But last year on that bike ride. I found out the hard way my bike is way too old to continue being used especially for something like that, without completely blowing out my legs (is has issues with its gears). I’m looking into mountain bikes as the middle 14 miles is off road. But the beginning and end are paved. I need some suggestions for bikes in the $400-$600 range that can do both paved and off roading well.