Wow Batsheva, it sounds like you are already off to a great start. I think with time, you will naturally improve. It's important to vary your rides. If you continue to ride the same pace, you won't get faster. Try doing some intervals. Ride with groups that are faster than you. Be okay with getting dropped. Each week, try to hang on a little longer. If you can't ride with groups, have a goal for each ride. I do a long slow distance, a tempo and an interval ride each week. I'm in FL also, so there isn't much in the way of real hills. I'll ride bridges to work on my climbing, but it really is very different than riding flats. I haven't found it to be especially beneficial to my overall riding.