cant get to multiplayer on pe 8.1

I'll assume you two are trying to play on a LAN server. To start off, you'll want to check the "Game" menu in your options to see if the switch marked "Local server multiplayer" is toggled on for the device which is hosting the world. Even then, if it doesn't work, something might be wrong with one of the devices, the network, or Minecraft itself. Oh, you'll also want to check if the host device has the world loaded when you're trying to connect.