Also, something that I've found is that if you go wrong somewhere instead of mindlessly searching for the error (assuming there are multiple or you don't know the error's location) just start from the beginning and go down seeing that if this works. If you see a break and something disconnects, in all probability that's where the error is. It's all logic.
With your index fingers you can feel a bump on the keys 'F' and 'J'. When you type you must get back to these two keys as soon as a key has been pressed on the keyboard so that you know all the time where you are on the keyboard. If you don't find the keys 'F' and 'J' again you will get lost and make a lot of mistakes. For the same reasons the first lessons are done without ever moving your fingers from these two keys.