When buying shorts, make certain no seams run down the middle of the crotch. The stitching should be recessed into the shorts so that you can run your finger along the seams and not feel the stitching. Next, you need to purchase a way to carry water. It can be a simple plastic water bottle with a cage all the way up to the popular Camel Bak which is filled with water and worn like a backpack. A drinking tube allows for hands-free sipping at will.
Cycling gloves are a matter of comfort but good ones absorb road shock and prevent numbness.
Begin slowly to warm up before reaching full exertion. Work up to riding one to two hours daily. If you are planning a tour, you want to be able to easily ride your bike, fully loaded, for the same number of miles you will be riding. You want to reach this goal by the beginning of the tour, not mid-way through it. The best training for a ride is riding, even a stationary bike if the weather is unfriendly.