Yes, lessons are VERY important. Even if you are experienced there is room for improvements! I did ride before, but started taking regular lessons with good instructors last year and only then I realized that I know very little about correct posting, cues, etc. Well, I knew some of course, but they were far from perfect. Of course if you just trail ride and your horse is well trained and you are confident you probably don't need lessons. So it all depends on what you wanna do.
BTW, I trailer my horse 1 hour one way to the instructor. So it's not next door either.