For Mining I have no idea where the pickaxe is can somebody help me?
The Pick you used to start with was probably just for encouraging testing of mining, and now that its been tested some, its more reserved to progress.
You can make your own Pickaxe with 3 ingots, get them hot and put them on the anvil, then radial select "Large Axes"
Hit it till a double axe head is forged, and then hit it again to turn it into a pickaxe head
Edit - Man Itch.io's post boxes... sure leave a lot to be desired :l