There's going to be some 'free' all over Xbox One and 360 Live this weekend, specifically between May 18 to 21. During that period you can play online without Gold membership, and there's also a limited time unlock of Minecraft: Xbox One Edition to play.
To get involved with the Multiplayer All-Access event you just need to log in, and obviously download Minecraft if you haven't already. Then enjoy a weekend of free multiplayer and block building. After it's over you'll have to cough up the cash or go do something else.
Still, if you've not paid to try Live before it should give you a taster, and if you've not played Minecraft yet then... wait, how have you not played Minecraft yet? How is that possible?