I'd like to make a USB powered device that can act as an Airplay receiver that plugd into my TV via HDMI so I can stream files from my iPad or iPhone. Think of it as a very cut down Apple TV

Inspired my mini Android PCs like a MK802 II what I want to finally get to is a USB memory sized stick that plugs into one of the USB ports on my TV to power it and at the other end is a HDMI socket. A HDMI cable goes from this to the TV. You'd simply select the HDMI input on your TV and stream.

So it would require:
USB for power
HDMI out
WiFi
Processor able to hand audio and video streams using Airplay
Some way of configuring it via an app or browser interface so you can get it on your Wifi network.

So question is how do I get started, I have very little knowledge of building electronic projects.

Looking for help to set me in the right direction.

 

First, get copies of the following standards:
USB -USB Implimenter's Forum
HDMI -VESA (I think)
WiFi - IEEE

Then start reading.

 

yeah that is NOT a simple project by any means.
That is "expert" level for sure.