How many times do I have to play a certain opening till I get it right?

Three thousand, four hundred and sixty-two. From there it's plain sailing.

Playing the opening a couple hundred times will get you the basic concepts of the opening and will help you play it. You must play the opening a couple hundred thousand times to really master the opening.

Use your own state of mind.

I think it would depend on the opening.  You could probably learn most of the normal variations of something simple like the italian game a lot faster than the sicilian defense.  I'm learning that (in my own games) the specific opening move order etc. isn't that important because usually my opponents and I either win or lose because of a very serious tactical error so I'm growing less concerned with learning the openings cold than I am with improving my other chess skills.

You need to study the best books on whatever opening you choose. At your level i'd reccomend opening books by players such as Keene and Botvinnik, players like this tend to explain ideas rather than give reams of theory. You will pick them up better this way.

opening are like relationships they start off hot and then turn luke-warm.  You can play a horrible opening and (most of the times) keep playing, you can make a positional error and play on but when you make and endgame error and your checkmated.  The point is study endgames, then middlegame plans and tactics, and finally openings its reverse engineering.

I pick an opening and not always considered the best by the masters. Like i have an obsession with the caro kahn. Its a closed game which i have always hated....but i am slowly getting over my claustraphobia or however u spell it...