Oops! Sorry, I didn't mean to assume so much.
Hydrometer: We've all sacrificed numerous hydrometers to the brewing gods. Just compare your reading to your expected final gravity, and assume that your starting gravity matched the recipe. the main point is to see if the beer is done or not. If its up at 1.020 or something then you know its got a ways to go. but, if you are at 1.012, it might just be done. Take a couple more over the next couple days, and if it doesn't change...I'd leave it alone.
Stir Plate: you don't have one, which is fine. A stir plate is a device that has a spinning magnet inside it. You place a flask on top of it with your starter inside, and another magnet shaped like a tylenol pill---called a stirbar. The stirbar is coated in inert plastic. Since the stirbar is a magnet, it gets spun by the magnet inside the stirplate. This allows you to automatically stir any fluid. In brewing we use them to keep the yeast mixed into the wort, and to maximize the oxygen that gets into the starter because it helps the yeast grow. In this case we don't want one, so you are good.
High Krausen: this just means when the yeast are at their peak of activity. Its visually obvious. You will see lots of foam on top, and you will see the yeast churning around in the wort.
Starter Wort: Starter wort should have an OG of 1.036 more or less. The usual formula is 1/10th of the water weight. So, 800 ml of water weighs 800 grams. So, to make a 1.036 start you dissolve 80 grams of dry malt extract in 800 ml of water. then you have to boil it.
In order to make a single starter, I'd recommend placing your water and DME into a sanitized, large glass container of some type. Like a half gallon jug. Something that is big enough to boil 800ml of wort without overflowing, and that will still fit into the microwave. Put some saran wrap over the opening, and then microwave the whole thing until it boils. then let it cool to room temperature. Once it is cool, add the yeast. Recover the top with a loose piece of foil. Let the yeast do their thing until the next day (12-18 hours). when it is all foamy on top, pour the entire thing into your beer.
When (if) you get into making starters regularly, you will want a 3000ml flask made out of borosilicate glass (heat resistiant). These can be heated directly on the stove, which is easier than the microwave thing.
WLP001 is White Labs liquid California Ale yeast. you can also use fermentis SAFALE US-05, or whatever the Wyeast equivalent is (I'm a white labs man most of the time).
