Support your passion but was just wondering how this built technology can bring extra benefits? You should first know how the current messenger works, what kind of significant problem that can be solved by blockchain so as to build up your idea which is reasonable to convince other to support and use your project. You should have sufficient support, no matter on statistics or on interviewees' point of view.

If you have no idea on how to build a blockchain, how does it actually work, you should study more on the concept and the technical part first. To build your own blockchain, i think you may try on the HyperLedger Fabric, I am also a newbie learning about blockchain development there.