Extracurriculars are VERY important in building a strong application! In fact many universities regularly will turn down applicants who only have a high GPA and no extracurriculars Extracurriculars are what show the true you to the universities you apply for! It's never too late to get started. Even if you don't have much experience, you can start tomorrow by joining some activities that you are interested. Join clubs that you are interested in. Doing so will show colleges that you truly dedicated. Also, I recommend some leadership clubs or speech clubs. These will show that you are good with people and are able to convey your ideas clearly and concisely. In doing so, you will build a much stronger application than what you currently have.