I'm intstd in selling short as there's a stock I think will drop, but i've never done it and am filled with trepidation. I head to options on my trading site and off the bat seem to have five...options...namely buy/sell to open/close and 'exercise'. I think I want to "buy to open" puts which iiuc are options to sell. If I take e.g. the $14 strike I'll pay $2.45 for the right to sell at $14, until April 14th. And I can then 'sell to close' (which I suppose means, sell the option) or 'exercise' (which means sell the stock at $14) any time till the 14th. If I 'exercise' I'll need to have bought the stock beforehand. Do I have all this right?
You're close but your explanation needs some fine tuning.
Creating a new option position means to 'open'. It can be 'buy to open' (going long the option) or sell to open' (going short the option).
If you buy the Apr 14 $14 put, you have the right to sell the stock anytime between now and expiration for $14 (exercise). You do not have to own the stock to do so, in which case you would end up with a short position in the stock as long as it was borrowable at the time of exercise.
You could also close the long put position by 'selling to close'.
A word of caution: The last few weeks before an option's expiration is a period of increasingly rapid theta decay. That means that unless your stock drops, much or even all of the option's time premium is going to be lost by 4/14 which is only 4 days away (the market is closed on Friday for the holiday). You really need to be right about this or it's a loser in no time at all.