Speed work can be improved by running hills/stairs.
Endurance can be improved by running. But not long distance, because in the game, you don't just run at one pace for the entire game. No, you are constantly moving forwards, backwards, side to side and at all sorts of different speeds. Fartlek running works best. Fartlek running is just mixing up your running.
Example: Run for 30 minutes straight, but in those 30 minutes:
-Jog for 4 minutes.
-Sprint for 30 seconds
-Cruise (75%) for a minute
-Sprint for 45 seconds
Get the idea? Just mix it up. But actually push yourself, don't jog for 29 minutes, then sprint that last minute.
Shot Power is developed by learning how to correctly hit the ball. I'm not a strong guy at all, and my legs are pretty small, but my shots are powerful. How? I hit the sweet spot: The exact center of the ball. It's really easy to adapt to, if you focus on it. Also, imagine how much more powerful it would be with a little more leg muscle. (Don't try weightlifting yet, at least until you're 16)
Bending,Dipping is created by your followthrough.
I'm guessing you want to know how to make it dip like Ronaldo? Well, there's plenty of guides out there for those who want to know. Here's one:
For your agility, it's all about acceleration, balance, coordination.
Here are some drills to help your agility from this site
For your defending, here are some threads posted by other users that I've found to be very helpful
I hope this helped. But with that being said, make sure you take a good look around this Forum and in the Training section. There's plenty of great tips drills if you take the time to look for it. Try the Featured Articles or use the Search feature.