I finally got the game a few days ago, I love it

I have already made a smallish settlement, but I keep getting afraid to expand whenever I heard the dungeon sound in my basement.
...Dungeon Sound?
I'm fairly sure what you're hearing are called 'Cave Sounds'. Also, if you are afraid of getting surprised by too many hostile mobs in caves, go in them at night. Apparently less hostile mobs spawn in caves at night because unlike daytime, they are also spawning on the surface. Beware of Lightning. Start a tree farm. If you are still on stone tools try and find Iron and upgrade to iron tools. Kill as many pigs as you can, setting fire to the block underneath them is an advisable way. Branch mine if you're not into caves. Make sure you can see around your house through glass. The roof counts too. You do not want to get damaged or killed by a surprise explosion. Try and avoid combat with skeletons until you have a bow and a decent supply of arrows, and if you can try and trick hostile mobs into killing themselves or each-other. (such as getting one to walk into lava or getting something like a spider to attack a zombie)
(IDEA: MLNO Minecraft server except it'll never happen)