You just open your inventory, select a furnace and put it into your inventory and then place it as usual
Shift while you place it.
You can't. The free mode is creative play only. No mobs, weapons, items etc. just infinite amounts of blocks to place.
No, the monster spawners are not available as a placeable block, even on Creative.
its just because you are in creative if you were in survival you would be okay!
Placing items in Minecraft is usually done with the right mouse button.
You can. Your computer is wrong.
No, you can only place and destroy blocks.
You can place coal in the furnace, then place any wood on the top slot to burn it to charcoal, or use a wood log on the bottom slot and one at the top and it'll burn that way as well.
You can't wear armour in creative mode. All you can do is infinitley place and destroy blocks.Actually you could by hacking minecraft... There might be a mod that can help do it that you could download, or you could just go into survival and put it on and then go back into creative.
You need to be in creative mode in order to input commands into the command block.
You have to make a furnace by filling in all the slots in your crafting table (besides the middle one) with cobblestone. Then you place your furnace and put sand in the top slot and coal, wood or charcoal in the bottom slot. This will make glass.
You can download a mod so you can place mob spawner blocks in creative. But that's the only way unless there is a hack at which you can