I've been hired as the UI & UX Designer for an app focused around online dating. Typically, I work with clients that have an existing solution, like a website or app. This gives me a jumping off point to conduct research on users and identify things like: age, gender, and education which I can then use to bring into the lab to discover what their motivations, needs, and expectations are. However, this project will be built from scratch with no existing customer/user base, which will make it difficult for me to uncover user motivations and create user personas.
So my question(s) to everyone is this. How could I get started with finding the right people for this project? What steps could I take to identify who uses online dating sites and apps, and what their age, gender, and education levels are without relying on Google?