If your in a multilayer game on someones else's server then you have to be an "OP" (a lesser administrater) in order to do anything other then look around.
If you are in single player some ores like, diamonds, redstone, iron, etc, need to have the right tool or an upgraded tool to break it the right way. Iron blocks need a "stone pick-ax" or it will just disintegrate without leaving you anything if you use a shovel, ax, wooden pick-ax, etc.
The mineccraft wiki has a lot of information there.
you dont they fixed it
i dont kno if u can change the blocks
You need to be in survival not creative, in creative you just break the block and dont get the resources from that said block.
wait for the police cars to come by then PK them but dont destroy them message me for a more detailed answer if you have trouble but this should help
no you dont destroy your game.
why dont you play minecraft
no you dont
You dont.
you dont
you dont.
I dont know
dont know