That's so exciting! Good for you! Hiking will feel different than anything else you do, so it will be somewhat of a challenge no matter what. BUT starting up a regular cardio and strength training routine will help your endurance and make the mountain easier to take on. I'd suggest anything that increases and keeps up your heart rate. You could jog/walk on a treadmill, and use the incline feature to simulate going uphill. Doing strength work for your legs will also help to prevent stiff/soreness. These are pretty general suggestions, but I've been a hiker for years and have found that while there is nothing else quite like it, being in better shape overall definitely helps. You're going to have a blast!! Make sure you bring something warm to wear at the top