Can someone tell me how to get an item with this Diamond_pickaxe # 2LP
With give can give
/ give @p minecraft: diamond_pickaxe 1
I don't know what you mean by Diamond_pickaxe # 2LP, but with this command you can give yourself a dia pickaxe:
/ give @p minecraft: diamond_pickaxe 1
The # 2LP is an id
But isn't the ID of a Diamond pickaxe 278?
Yes actually but she has enchantments and such
An id in Minecraft is always just an integer.