I've been playing Terraria for a few hours. I've got the basics understood - I've built houses for NPCs, explored, mined resources, etc.
At this point I've got a gold Broadsword and some Copper armor. I keep reading about cool stuff on the Terraria wiki, but nearly all of it comes with caveats like "you'd better have a full set of <ridiculous armor> before you try this!"
My question is: what do I do now? I can mine more gold/silver/iron, but that won't improve my gear by much. I'd like to find a Floating Island, but I have no easy way to fly or find them short of using a mapping tool. I'd like to check out the Dungeon in my world, but there's no way I'll be able to defeat its boss with my current gear.
I'm just not sure what exactly my next move(s) should be to progress and get my character to the point where I can explore these advanced areas.