Your domain name is not "pretty". You should not use something like .wordpress.com/ .blogspot.com or .boards.net for your website. Use a good hosting service, they normally provide you the first domain name for free.
I think you got good solution from above answers from @daica85 and @alton root. You just need to
Step 1 - Use your own domain and hosting service
Step 2 - Post the most engaging and relevant questions
Step 3 - Invite members via email to participate in discussion.
Free and fast marketing ideas
Create a free "Google My Business" account.
Publish (and participate) on social media.
Mark people (and brands) on social media.
Don't sleep on LinkedIn.
Do some local search engine optimization.
Develop an email marketing plan.
Create data-rich charts.