1. I think you have enough time, as long as your schedule allows you to to ride at least 2-3 times per week on a regular basis.
2. The fastest way to increase endurance on hills is to ride hills as much as you can.
I did the Livestrong Challenge in Philadelphia five times and that's a long hilly ride. I generally ride twice a week. I trained for the Livestrong rides by doing a relatively short, hilly ride one evening each week. My route varied from 16-20 miles. On weekends I did my longer rides, which were a mix of hills and flats. This worked pretty well for me, and although I haven't done a Livestrong ride in a while, I still like to do the weekly hill ride, because it keeps me ready for any terrain I might encounter on my weekend rides. I average about 14 mph on longer rides that have varied terrain, but closer to 11 mph on the short hilly rides.
Also -- I'd recommend getting used to the new pedals on flat, familiar terrain. It's easier to clip out on a flat surface, and you'll want to make sure you're comfortable with them before you add the hill aspect.
And, welcome to TE!
- Gray 2010 carbon WSD road bike, Rivet Independence saddle
- Red hardtail 26" aluminum mountain bike, Bontrager Evoke WSD saddle
- Royal blue 2018 aluminum gravel bike, Rivet Pearl saddle
Gone but not forgotten:
- Silver 2003 aluminum road bike
- Two awesome worn out Juliana saddles