It's a scary place to be. I've been there before. I know this sounds tough, but, let them laugh. You have your vision and you will achieve it. They have their own vision. Let your manifestation crush them. I promise they won't laugh long.
To all the people too self-conscious to join a gym:
If you saw someone who was illiterate trying to learn to read, would you laugh at them, or would you be proud of them and rooting for them to succeed?