3. Training has evolved into a complex and at the same time formulated science called "periodization", which is too complicated to explain in a couple of sentences on a message board like this. A great source for learning how to train is to read a book like Joe Friel's The Cyclist's Training Bible
. It helps you understand the science behind training. And, most importantly, it helps you set up an actual training plan so that you aren't riding aimlessly. You plan out your entire riding year. Each training ride has a specific purpose during any particular week, and each week has a purpose during any particular month, and each month has specific purpose during any particular training cycle. (Obviously you make adjustments to your plan as you go depending on how you, personally, are responding to the program because not everyone responds to training in the same way, and we each have individual strengths and weaknesses.)
Plan your rides. Ride your plan. Understand that the learning curve is quick as far as racing skills and tactics are concerned. But the fitness curve is slow, especially as your fitness improves. Don't expect instantaneous results.