Congrats! It sounds like you are making a GREAT start on your weight loss... Best of luck to you with the rest of the "journey," hehe. And 6 lbs is a pretty big accomplishment! Heck, when I first joined this site I made a thread to celebrate when I lost my first 4 lbs, so don't feel silly about starting this one. It's important to celebrate EVERY step of the way, to remind yourself what an awesome thing you're doing for your body.
Ps. It sounds like you've already made up your mind about your first mini-goal (dropping a pants size is a great thing to aspire to!), but just to give my $0.02--I agree with the above posters who said you shouldn't necessarily put a time limit on it. You can challenge yourself to do it quickly, sure, but of course you have to keep in mind that it's not a race! That sounds corny, ha, but seriously the most important thing is to lose it healthily, so it'll actually
stay off. It seems to me like most people set their mini-goals as a certain amount off of their starting weight, so they celebrate every 5 lbs lost, or every 10 lbs lost, etc. Personally, I wanted my mini-goals to feel REALLY special, so I'm doing every 20 lbs (except for the next one--after I hit 223, my next goal is ONEDERLAND!!) so they wouldn't be as often, but I can really relish them! Hehe.