What equipment do I need? What skills are needed? Where do I find clients? How do I get paid?

I'm still young but want to start strong, I love animals, kids, and don't know where that lands me, (I know out there). If I wanted to start a business what should I look into and how would I start?

See I want to start my own gym but I am not completely sure where to start. If i find a vaccant building for sale could I start there, will i have to pay taxes or bills every month or something, and how much estimated will i need to start with to pay for equipment, hire help, water, heating and cooling and everything else, how will i pay for all of this before i get costumers?

I know that is a very loaded question. I will narrow it down. We know what type of business, the location, the name. The only things I am stuck on is how much is business liability insurance and what department do you need to go to for registration of the business? thanks!