How do you play minecraft with a person on the same wifi?

Answer 1

you need to have two accounts,

if you mean together on a server you still need two account and

then one person must then download the mine_server.exe. from minecraft.net after which rune the exe file. then both people must join the server.

Answer 2

Once in the same wifi, go to the friends tab next to your world's tab at the top of the screen. One of you should go into a world. The other person must click on their name in the friends tab. Then you will get on their world.