How can I determine my XYZ position?
Solution 1:
If you don't want to use a mod, you can enter the following command:
/tp @p ~ ~ ~
That teleports you to where you are and it would say in the chat:
Teleported [your username] to [x], [y], [z]
1.12 Update
You can show coordinates on the screen as long as gamerule showCoordinates is true.
/gamerule showCoordinates true
Solution 2:
What I do is I use block launcher, as it allows you to install and use game mods. One of the mods I have is called smooth minimap, it adds a small map to the screen, it also displays your xyz in-game.