Once you find some crypts and set up a close base and portals then kill the Elder.

Once you start with iron just make the shield, mace and pickax. Make frost resist mead and head to the mountains for Obsidian and Frost Glands to make freeze arrows.. they do extra damage to wet enemies so they pack a punch in the swamp.

Also make some nails for a longship and start serpent hunting for serpent stew.

With experience, or you may just get lucky, find some silver and start working on that stuff.

Once you get a feel for where to dig you won't even need to do the swamp boss

Edit add - the main advantage of going for silver right away is that if you kill bonemass first you enable the Event for Wolf Hunt.