My wife and I are interested in building a multi purpose function hall . We have a lot of equity on our home. We do not have a lot of experience, we need somebody to advise us on how to go about this project.

Having been involved in two major home construction projects myself...

Start by thinking through what it is you want.. approx square footage, fireplace, window styles, ceiling style, any special features you would like, etc. Then go to an architect for a consultation - an architect can determine the structural aspects of the project, will probably come up with some suggestions that you may not have thought of yourself, and check zoning requirements. Do you have a builder in mind? Ask your neighbors and friends for recommendations, and be sure to check the Better Business Bureau. Your builder will be able to get the necessary permits and should have some good tradesmen he works with on a regular basis (plumber, electrician, mason, roofer, etc). In general just take it slow, ask a lot of questions, and remember that it's your home, and so you need to thoroughly understand all aspects of the project.

I would suggest contacting score.org and sba.gov for startup help.

You need to find a location, get an architect to draw up plans. Get local permits. And much more.