When you first join minecraft, its a perfectly natural accurance to soil yourself upon pressing F3, however eventually you need to learn how to use it. (Just like you need to learn that Krisst isnt real - just a figment of your crazy admin obsessed imagination.)
First of all, heres a breif explanation of what pressing F3 shows:
Top left corner ---
Minecraft Beta [Version] <How many frames per second or FPS you currently have> <Number of chunk updates>
C: Technical stuff. (Ignore this.)
E: Technical stuff. (Ignore this.)
P: Technical stuff. (Ignore this.)
Now the important stuff:
x: <Your position on the X-Axis>
y: <Your position on the Y-Axis> (This just shows how high or low you are on the map.)
z: <Your position on the Z-Axis>
Top right corner ---
Used memory: [How close you are from getting the minecraft ran out of memory crash] (Ignore this bit.)
Allocated memory: [How much memory youve given minecraft to go on] (More technical stuff.)
That scary bar at the bottom left, or for some, covering the entire left side of the screen ---
Remember how up at the top left it showed how many frames per second (FPS) you were getting? Well this shows about the same thing.
This bar shows the performance minecraft is running at, if it is very wild, red and high it usually means your computer is.. er... well.. bad. If its nice and low, (or maybe even green), then your computer is performing well running Minecraft.
Well now that you understand everything around the numbers we're looking at, we get to the fun bit! Yes, all that enthusiastic reading you did of the last section was only leading up to the most interesting section of all.
How to navigate the map using the X and Z coordinates:
Step 1: Press F3
Step 2: Guide your eyes to the top left corner and read the coordinates X and Z.
Step 3: Mark down the coordinates you just read. (You can ignore the numbers after the decimal point.)
Step 4: Move 10 blocks - You will notice your coordinates have changed from the ones you marked down.
Step 6: Move around with F3 on - look at the way your coordinates change as you travel.
Keep doing step 6 until you have a good idea of which direction changes which coordinates.
Step 7. Move in the correct direction you worked out in step 6 until your coordinates match the coordinates you want to reach.
Watch out for a - in front of the coordinates - It make a big difference!
This is what confuses some people. Eventually, if you keep going in the direction which shows the - coordinate getting smaller, then you will eventually transfer into the + coordinates.
For example, pretend these are my coordinates. The "X" is exactly on the map border:
X: -2500
Z: -1000
If I were to travel 3000 blocks along the X axis, away from the map border, my position on the map would be X: +500. This is because I have passed the imaginary line separating the positive and negative sections of the map.
(Remember even if the X and Z are not given, the X will always be said first)
Now, the map of coordinates is open to you! Fly! Dont flyhack though.. Just run... At a slow jog... Yeah, keep going!
Thank you Grapenomma for making this guide btw