with the new update all you need to do is:
if there is an available world to join you go to the end of the list of your worlds and if there is, the name will be in blue. just tap on it and there you are, you've joined someone else's world. theres also REALMS but you need a minecraft account and its really hard to get onto a server anyway as there are so few.
hope this helps. :)
P.S: if you havent updated yet i think that you also need to have the SAME wifi
hi bob! I have a kindle and I can join game with any thing but xbox and pc
when u want to play with someone have them get in a world 10 feet away from u and u will see there names in blue on your world list tap it and you will be in there game ( :