When Your Opponent Does Weird Stuff

We are on an online chess site, so people will play all sorts of weird things.
As a new player trying to get a grasp on some openings, it is always a little disheartening to have opponents play like h7 or something weird off the start after I play e4 and then follow it up with a series of weird moves.

What should you do in the mean time (while they set up their odd defence)?
I have heard people say just set up your opening as well as you can, and people say, just take as much space in the centre as you can while they are messing around on the edges.

I know it varies game to game, but what do you do when an opponent plays a weird opening (that might not even be an actual opening) that you have little to no experience with?

In my opinion just play with your knowledge of opening principles, like one that you said yourself, controlling the center.

It depends how weird it is. If it is a sideline, you should normally compare it to what you know is the main line of a specific opening and look for possibilities to exploit it. If it is completely weird, I'd follow ChessInstinct's advice, just focus on natural development and probably don't overthink it. The longer you play the less you will worry about "weird" moves.

1...h7
2...g5
http://de.lichess.org/BShL7ISg/black#3
ChezzwhizCup last game 2400 vs 2800 (winning within 15 seconds ) - weird,? maybe, he surely got his reasons playing this. I just wonder what the openings be with 0-5s complete gametime ;)

(#2) It's right controlling the center is the main focus, your opponent may be setting up an odd defense or offense, if you lose the game watch it and replay it and look for your mistakes. It's good to realize what strategy your opponent is using so you can outplay that opponent the next time he uses that "odd strategy."

After the games you should analyse the moves with the Lichess Opening Explorer. Some openings have refutations that are difficult to find during the games, but once you see the refutations you won't forget them.

I always enjoy seeing players do that. As beginners we learn the importance of controlling the center, developing our pieces, and castling our king. Opening theory comes in because it's assumed that both players are trying to do these things, so we have to engage in a battle for our own goals. If our opponent allows us to accomplish these things un-contested, consider it a blessing!

Stronger players often play unorthodox opening against weaker players - take them out of the book and then crush them with their superior understanding.

It's best to follow opening principles like ^ ChessInstinct said..