First time hiking, need some help please.

Hey everyone, there's about 15 of us planning a 3 day hiking trip in September. We're interested in leaving the car somewhere and hiking to a camp ground. Do I have to call and make reservations ? It says over 10 people you need a permit. It needs to be a beginner hike as some of the people have never gone hiking before. What would be the best place to go? Also how does the whole process look like? Thanks a lot.