I already had my own website when I opened my etsy shop. If you're starting brand new I'd recommend having at least 5 - 10 items ready to go in your shop. An empty shop is a big turn off for many buyers. You don't have to list them all at once, but aim to get a bunch up in your first week.
It may take a while before you start selling, it could be instant but it may take a month or even longer. It depends on how much work you put in to getting your items seen and your name out there.
As for crochet items, there is a fun tool called "Pounce" in the etsy buy seciont that lets you see what has been recently sold. You can also browse by category to see what's available for sale - this might help you figure things out.