You would deposit HIVE, then use that HIVE to trade for other tokens on the platform. Search for the token named "PLOT", then place a buy order using the HIVE you deposited.

Plots are currently going for around 11 bucks on Hive Engine I think.

Once you have a Plot token, you can send that Plot to your game account anytime from the Collection screen. Since you already have a Plot, click the menu icon for that row and select "tokenize". You will then be able to send the Plot from Hive-Engine to your in-game balance.