Unmotivated Kids!

Well It has been over a year since my last post. A lot has been happening! That pregnancy, well I was right it resulted in a girl! Sophia Vera is her name and she is a wonderful sweet angel! She is 9 months old today! She is absolutely perfect! My boys on the other hand...just kidding they are wonderful also. Babys are just well easier. I have a 71/2 year old and and an almost 5 year old. My oldest said mom I want to take guitar lessons! For a year he begged for guitar lessons, so I finally said okay you understand that you will have to practice everyday? He said yes I want to play the guitar! So I have a brother who plays very well and he is teaching him, so far so good. A year later I am constantly fighting with my son to get him to practice! He groans and cries and I just didn't realize just how hard it would really be. He is so unmotivated to do anything except watch TV. He doesn't like to do anything he'll have to exert energy for. Also my younger son is the the same way. He wanted to sign up for soccer with his friend, but we missed the signup deadline and paid a late fee, 90 bucks later he just walks around the field pouting! I understand that 4 year olds don't understand money and follow through, but what could we be doing wrong here? The other kids on the team run and play and atleast try, no he won't even try at all! AHHHHH Also all they do is whine about everything, what meals we eat which places we go...I feel like Eore from Pooh Bear and there is a black cloud over our home. I don't want to complain I just don't know what to do! I try to be positive with them and tell them that once they try and learn how to do things it will be fun, to no avail! Gosh when I was a kid I spent almost every waking moment outside running and jumping and biking and just having fun with whatever kids there were to play with. I just don't know what to do with them. We are trying banning the TV. For the whole house! We'll see how that goes and I will post our progress.I feel like I am screaming all the time, no one listens when I speak normal, quiet, or loud. But I still scream, I know I am part of the problem! Probably a bad example! Any suggestions would be welcome!