Topic: Just learning need help

Just bought Xbox X for my 3 grandsons. They love playing Halo so I bought Halo Infinite. Can not figure out how they can all 3 play at once ( against each other ) . Xbox 360 was easy for them with the Halo 1,2, and 3 as they just turned it on and started playing. Need someone to help me out with step by step instructions please. They are 12 and 13 years old but they do not know how to set it up either. Do I have to sign up for an Xbox live acct?

@Maddog1958 This article explains it better as a step by step than anyone here can, I'm sure!
https://www.digitaltrends.com/gaming/halo-infinite-how-to-pla...

They'll each need an Xbox account to log into (no guest accounts.) Paid subscription shouldn't be necessary for local multiplayer, though.

Oh, I hope you've managed to set everything up properly. But is someone else playing Halo? Seriously?