WASD
E for inventory Q to throw
[Space] to jump
[Shift] to sneak/not fall off ledges
[Ctrl] to sprint (Or Wx2)
(I'm not sure about the mouse, I have been playing MC to long to describe it.)
Also note: I doubt this will happen, but if 10 people get on at the same time no more people can join. I am saying this because we have reached 12 people invited (I can invite more, just 11 people can't be on simultaneously.)
It's because the infinity update has so much generation going on. Mine can't either, albiet I get like 5 fps and was able to go to the evil aether dimension and it sums them up pretty well: Phantoms, bees, and a bunch of chaos.