Starting a social network

I’m thinking of starting a social network for a certain type of partner dancing. It’s a niche I know is not currently being served, and I know there is demand for a comminuty site from consumers, and probably suppliers looking to contact those consumers. I’ve made websites, but am new to making social networks. This would be a hobby, that I wouldn’t have to much time to spend on. I was hopeing to buy a domain name, spend say 20 hours setting up a site, seeding it with some starting entries,…