I'm not a runner, but last January I started doing some shorter fast paced runs and interval work.
I got tested for a 1.5 miler and pulled 8 min 49 by the end of January, and this was after a 1.5 mile 'warm up' and other body weight based work.
I put on about 3 pounds as well (I was running prior to breakfast, so fasted cardio, however I do like my breakfasts

), which meant my weight went up to about 87kg.
I will step aside for runners comments though, because I just run for the fitness aspect, not to be a good runner (a tool and all that).
edit- like the maiden said, I would advise dropping lifting if you have sub 2 months, but if you have longer then that, I would keep it (although again, that depends on where you're starting out and how new you are to lifting...and your age).