1. Get The App
Get the app from Apple App store. It comes ready loaded with a couple of Unit Lists but you can create your own in no time at all. You only need one copy of the app to play a game for two people. All updates to the app are delivered for free as soon as they are available. There are no in-app purchases.
2. Prepare Your Miniatures
Company Commander has you in command of sections of infantry and vehicles (tanks, troop carriers etc). The infantry are best based on 40mm sqr bases for rifle sections then 20mm sqr for weapons teams (mortar, sniper etc). Vehicles dont need to be mounted. A small engagement consists of around 6 sections of infantry, 2 weapons teams and 2 or 3 tanks (per side)..
3. Get a Table Ready
You need a flat surface to play, minimum is about 1m sqr but more space provides greater opportunity for tactics. The AR capabilities work best in good light so make sure there is enough. Then use what ever scenery you have to create a battlefield for the opposing forces. Adding lots of cover (fences, buildings and forest) provides lots of variation in how battles play out.