Copper deposits go under the ground. Keep digging to get more.
Horde all the honey you can, you will need a lot later on for mead.
I have not encountered a sea monster yet, but I always sail close to land just in case.
When you have copper, most enemies that have a weakness will be for blunt, so get a mace rather than a sword.
This is my base. I built it on the sea where the land stretched out into the sea a bit. I had a build the wall when attacks started to happen. I recommend building the platforms so you can shoot from inside the walls.
In retrospect, it would have been fine to make a tiny forward base, then take time to build a main base right in the middle of a dangerous area. You'd need walls, but taking all the wood would clear the land around the base making it easy to see and clear enemies before you go out.
I want to base build like that when I go to swamps next. Everyone says it's a rough area. Im stocking up on high quality foods now then going to set sail to find a swamp, get a quick base, then build a main one deep in the swamp.
How do you change that special power you activate? Mine is stuck on the elder as you see in my screen shot, but I want to change it back to the first one.