Make some real business and publish it from your website. You can build your community with your early adopters and customers.
I mean how to build communities before having nothing.
It's all real project. Not scam. but people told me that it's just on paper, when having exchange, they would PR for me. I need KOLs and communities come with us when nothing is in my hand Anyway you should create some kind of page/channel/group etc. in social networks and messangers: facebook, twitter, telegram, steemit, discord, whatsapp bla bla bla...
Then you can start contacting people that could be interested in your future project and ask them to join your resources.
It is the only way, IMHO.