This is a great initiative! I remember struggling to learn Relay, I love it though, used it in some toy apps and will use it in some upcoming projects that I have. However I have a few issues with Relay: the main one is that it overall discourages people from starting with GraphQL. From creating a Relay-compliant GraphQL server to adding it to your app, Relay forces you to good conventions that, unfortunately, requires you to learn about its concepts and makes it super difficult to ramp up fast.
For anyone interested in working with Relay and GraphQL in general, I would advise you to start first with just learning GraphQL, without Relay and its constraints. You'll see that much of the issues you may have with GraphQL may come from actually trying to comply to Relay. Once you are okay with GraphQL, then, you can move to learning Relay.
Finally, I want to insist on the fact that GraphQL is just a specified language that can be consumed by any client you need/want. Relay is made by Facebook, for Facebook, which is a cool thing but may be a bit too much for your simple app or may not be adapted if you are migrating a legacy app to GraphQL (which was my case). That's why you should take a look to alternative clients as well (Apollo [0] for instance ;-) )!