As an iron man you would need something like 80 mining just to get the rune ore and like 95 smithing in order to get a rune pick axe. If you aren't mining with Rune you aren't really mining at all imo
As for where to start - literally anywhere. It's a game. Enjoy it. The more you look into optimization and instruction the less of a game it's going to be and more of a job it'll feel. Sure I could tell you to kill cows to level your strength up enough to 1 hit them, but where's the fun in that? Go discover your own path
You can just buy it in a shop... Nurmof's Pickaxe Shop for example.