If a font is listed in the 100% Free does it mean I am able to use it for commercial purposes? Or I still need to contact the creator?

You should still contact the creator/copyright owner. Permission to use a fond generally depends on how you are going to use it.

100% means free for every purpose. But always check with the author, the EULA may vary. (ex: you may not be authorized to use a font for religious purpose)