YC alum, Catherine Cross, tweeted out about building a community on TikTok. Don't get bogged down in too much marketing and promo language. Do your research and get an understanding of what will compel members of that community to be interested in what you're doing.
YC's Kat Mañalac wants to change the way you think about launching. In her talk, she shares the multitude of ways to launch and get attention for your product, with tangible strategies and examples from companies like Airbnb.
Apply to Y Combinator: https://www.ycombinator.com/apply/