Making friends on Blurtit is pretty easy. Just engage with other people, help them out when they have questions, ask questions of your own that are challenging, interesting, and engaging.
Also simply "following" people that look interesting or are into the same topics as you is a good idea.
I'd also suggest only using the "anonymous" function sparingly.
You're unlikely to make many friends on Blurtit if they can't work out who you are!