First of all, age is not a limit in North America, do not be discouraged by others.
Secondly, if this is your dream school, apply it.
Thirdly, prepare for some backup schools just in case. MBA application is very time consuming (preparing tests, writing essays, etc.) Make the best investment of your time!
Other comments: you can't control college GPA so don't worry it. Give GMAT your best shot, but don't waste too much time on it. Your personal reflection matters so much more, especially for the GSB. Your story and your recommendations are important so make sure you spend time thinking through what matters to you most and why, and how you want your recommenders to share your story.
Aspirations and inspirations are not defined by your chronological age so don't worry about what others tell you - life is too short to not give it a shot.