You need 14 obsidian. These can only be mined with diamond pickaxes, and are made when water runs into lava. When you have 14, place them out like this (O = Obsidian, E = Empty):
O O O O
O E E O
O E E O
O E E O
O O O O
Then you need to set the inside of the portal on fire, using flint and steel. Flint and steel is crafted like this (I = Iron ingot, F = Flint, E = Empty):
E E E
I E E
E F E
And by the way, "the other world" is called the nether ;)
For a nether portal, create the following on the ground standing upright:
[x] = obsidian
[ ]= nothing
[ ][x][x][ ]
[x][ ][ ][x]
[x][ ][ ][x]
[x][ ][ ][x]
[ ][x][x][ ] and light it with a flint and steel. An Aether portal (mod required) is glowstone, and activated by a bucket of water.
To make a portal to the nether, make a 5x4 rectangle of obsidian and light it with flint and steel. To make a portal to the end, you must find a stronghold using eyes of ender and then you must activate the portal inside using 12 eyes of ender.
Build a frame of glowstone that is 4 blocks wide, and 5 blocks high. Then, place a water bucket on the bottom of the frame.
4 by 5 redstone block and put lava inside
Make a 5x4 Portal going upwards of obsidian.
Make a nether portal.
You can't
No
No, sadly you can not make an Aether portal on the Xbox Edition of Minecraft because the Aether is part of a mod. As of now, the Xbox Edition of Minecraft does not support mods.
to make a portal to heaven you need glowstone and put the water in it
Make a nether portal.
No
Well, unfortunately it is impossible to make a portal gun without the mod. Sorry.
Those do not exist in Vanilla Minecraft. There may be a mod that allows you to do that.
Idgaf
get a nether portal and use netherrack