Just ride, it'll come. Don't bite off too much at first; just like with weight lifting, it's better to spread a load out over a few days than to kill yourself one day and be too sore to go again. You get stronger by recovering from training, not just from the training itself.
That being said, you'll pretty quickly be able to do whatever it is you need to do, just watch out for saddle comfort and make sure you can handle any big hills (up and down). Enjoy.