Hello,
You are likely qualified for your target programs – if so, they will still be
reasonable reaches of varying degree, simply because of how competitive they are overall.
A key factor in your competitiveness will be the
quality of your work experience – i.e., did you excel and demonstrate outstanding performance, leadership, impact, and achievement relative to accomplished peers in your various roles? Can you provide evidence that your career path has been in some way fast-tracked? This factor will be important to these adcoms – not just what you do, but that you do it with distinction and high achievement.
As for extracurriculars -- adcoms are very skeptical about community service that suddenly starts just months before application time. It actually looks worse (because it seems cynical and insincere) than a lack of such activity. So perhaps rethink this plan. Instead, delve into your actual experiences to find some evidence of contribution, even if it may not be hugely impressive -- i.e., are there informal ways that you've contributed to your various communities, such as at work organizing social events, or gathering friends to help another friend in need, etc.? Even nothing is better than something that gives the impression it's being done for resume/application enhancement.