Copper can be very plentiful or scarce .. it really is RNG.
I scout my worlds before I commit to a base location. For Black Forest for Bronze I will look for an area with 5 or 6 copper nodes near each other close to a shore for tin.

But scouting and building a base there I avoid having to search the map for some copper.

You can apply this logic to any further development as well. Like finding a copper node to set up a refining base next to a swamp with lots of crypts.

You can even find copper nodes that are more than one big boulder. Multiple may be attached to the one on the surface. Always a good idea to excavate the area to make sure you get it all.