I don't understand the process of how you expand your league to 32 teams. :

Expansion can only be done on one date in the game which is June 20th (if you need a reminder on that at the top of the screen there is a calendar icon which will bring up important game dates when clicked on)

So on June 20th in the game go to the upper right corner where your player's name is, click that and a dropdown will appear that lets you go to the commissioner office. Switch to commissioner and then you will see on the commissioner office screen an option to start expansion in the section under LEAGUE OPTIONS and just follow from there.