Thank you for your interest in WikiTree.com and for asking your question here at G2G. My answer is based on the notion that you are new to genealogical research. Here goes:
Start with what you know of your ancestry and record it on WikiTree, keeping all profiles for living persons at the most private setting. (Red circle).
Search your ancestral surnames here (at WikiTree) such as: http://www.wikitree.com/wiki/Keiser-85 and contact the Profile manager(s) if it seems to be a profile for someone you are related to.
Also, you will want watch the excellent getting started video here: Getting Started on WikiTree.
Continue to ask questions here, at G2G, and use the Help Menu pull-down feature at the top left of each (any) WikiTree page or screen.
Beyond that, ask any of the Mentors or Greeters that helped you to sign up.
Use the free search sites, such as Family Search.org to search documentary sources for your ancestors.
Thanks again and Good luck! I hope this helps.
PS - This G2G question from January seems to involve some of your people. Who knows?