Once I actually have some money I'm probably going to pick up Starcraft 2, but I  have a couple kinda dumb questions
Okay, so I don't know a single person who is going to get this game, except my brother who said he might get it, but maybe not.  So will the mulitplayer still be fun since I'm probably going to spend most my time playing 1v1, because I don't like playing with randoms?
Second, I played Starcraft, but I remember absolutely nothing about the story, do I need to catch up on the story in the first one If I want to enjoy Starcraft 2's campaign?
Do people use mics to communicate in this game, or do most of them just use a keyboard?  Because I will just use a keyboard if I decide to try some team games or something, and I don't want to keep getting kicked because people will only play if you got a mic.

1) There's a fairly large community of people here that have the game, so you can add them and play against them. That way they're not total unknowns like the people you'll play against on the ladder.
2) Not really. They do cover the broad strokes of what happened in SC1 when you install the game. Perhaps a refresher on the story from wiki or something should suffice otherwise.
3) I've not really heard of many people playing using mics (unless they're playing with people they know IRL), so you should be fine using just your keyboard.