Command blocks can only be obtained using the give command and can only be successfully used by server operators in creative mode.The command block will perform certain commands when it receives a redstone current, these commands can be set by right-clicking on the block.
the possibilities for commands is endless in bedrock edition as long as you know how to add your own custom commands using command blocks which you can get by typing /give @s command_block
If you're using WorldEdit. The command is, /tree redwood
Leaves can be harvested using Shears on a tree's leaf blocks.
You can fill the up with blocks or you can collect it using buckets.
Unfortunately, using the /give command will only give you a pig spawner.
You cant find a giant mob in vannilla minecraft but you can sumon him using a command or a spawner.
you cannot craft one, you will need to make it using your imagination using blocks etc
You can dye wool with it, or you can create decorative blocks of it using 9 pieces.
Maybe you're not using a pick to mine. You need to use a pick.
it totally depends on the server
You cannot teleport home in vanilla, no cheats Minecraft. However, in many servers there is a /sethome command which allows you to set a home and teleport to it using /home.