Just got minecraft what should I build my house with?

Obsidian is so hard to get, mossy cobblestone is even harder, make it out of Wooden planks/cobblestone… Wood looks better and provides same mount of protection as cobblestone does.

An obsidian house will take you AGES to build, let alone find and mine. You're going to be digging for a while and you can't mine obsidian without a diamond pickaxe. When I first got started I just built my house with stone, cobblestone, wood and glass. That would be good for a beginner.

First make sure you have a house that's made of anything like dirt even THEN start planning your final home. I suggest a mix of cobblestone and logs but for sturdiness use cobblestone.

I start with something basic like wood planks or dirt and then move to cobbleston then to stone bricks and then accent that with decorative things like blue wool or some other colored item

Your initial house is probably going to be made of dirt, cobblestone, or wood. That is if it isn't dug into the side of a hill.

Obsidian is hard to get a very expensive, you need at least a Diamond Pick to mine it. Even then it takes a long time, so Obsidian should only be used as housing material in the very late game.

While Mossy Cobblestone is technically easier to mine, even a wood pickax will do it, it is usually very rare except in the latest version where you might be able to find more in some specific biomes.