First Mirror Update

Hello! This is my first post involving my smart mirror project!

I've been looking into which parts to buy for the project and here's my running list:

HP Pavilion 21.5-Inch IPS LED HDMI VGA Monitor link
CanaKit Raspberry Pi 3 with 2.5A Micro USB Power Supply (UL Listed) link
Mirror?

Right now, I'm not sure which order I should do this project in: Start with software and then build it in the mirror Start with the hardware and then make the software work

I guess I'll decide that once I get the mirror (which I'll be getting when I go to Home Depot, fingers crossed)