Originally posted by Sabaithal:

Considering killing the first boss is necessary to get the basic pickaxe, and you can't get any other pickaxes without the basic pickaxe, pretty sure that's where you'd be softlocked.

You essentially can neither build nor use anything that requires mined ores/material.

Trolls can mine for you. You can then find iron buried in the swamp or by killing oozers, and in the mountains you can use the stagbreaker or iron sledge to find silver.