Note: You can only get achievements in survival mode only! Also achievements in this game can be buggy, so give it some time or keep getting materials. You need them anyway.
To make a pickaxe, you will need at least 2 sticks and any kind of material. To be exact, any wood, cobblestone, iron, diamond or gold. Since its on the PC, you'll be using the classic settings with the 3x3 settings. To create a pickaxe, place your material on the top row, then place the sticks in the middle going down. Hope this works out. ^^' For more help, visit the Minecraft Wiki.
Here is a little graph or something..idk of what it should represent. The X's represent the Material and the O's represent the sticks.