You need to have the block selected then right click to place it in front of you, to place it underneath you jump (space bar) then right click fast
press where you are going to put the block.
1 Block is a cubic metre, so 1km is 1,000 blocks.
To place blocks in minecraft, right click. To destroy them, left click.
Place two blocks of stone, one above the other. That has to be regular stone and not cobblestone. Stone can be made by smelting cobblestone in a furnace.
If you consider breaking and placing blocks and killing monsters educational, then yes.
You shift click on the block and place it where you want it
If you're just crafting by hitting the "I" or "E" key, then you need to craft a workbench by putting 4 wooden planks in your 'craft box' in your inventory then place it by right clicking and then your craft box is expanded to 3 x 3.
Flam can burn blocks( like,wool,woodetc.). It can also hurt mobs.
You can't craft anything with them, but they can be used as floating platforms when you make a farm, or to cross water without using blocks.
You are unable to craft command blocks in minecraft, but if you have cheats enabled on your singleplayer world, you may type /give {player} minecraft:command_block
place 2 wooden placnks going vertically in the crafting table :)
right click on the block in which you want to place the block