Ever since God created man he has given us commandments to follow, When He created Adam he told him not to eat the fruit of the tree of knowledge of Good and evil, because he shall "Surely die" (Genesis 2:15-17)
These commandments that God has given us all have a reason, He didn't think "Oh I know, I will tell them not to murder each other because that will be fun" he gives these commandments because they will help us to live happier more fulfilling lives and not cause the world to suck for all of the other people who are living in it too.
Since God is our loving father in heaven, he wants the best for his children, he wants us to be happy and he knows how that is best achieved. Not only do these commandments help us all to live happier lives and to get along better with each other but it is through following these commandments that God blesses us. In a revelation given to Joseph Smith we learn that all blessings that come from God are dependent on our willingness to follow His commandments. (Doctrine and Covenants 130:20-21)
The commandments are also there to help us reach the final goal that God has for us, This goal is perfection. God wants us to be perfect, he also knows that we are not able to get there with our freedom to choose by simply clicking his fingers, he could make us instantly perfect and stop us making mistakes but that would also stop us making decisions for ourselves and so He has given us commandments as a stepping stone to perfection, of course we make mistakes with these commandments every day this is our nature but God is there giving us the next step on our journey to become perfect like He is perfect.
And finally these commandments are one of many ways of finding out finding our for ourselves if God is there, Jesus Christ taught if we do what he asks we will find out for ourselves (John 7:16-17) As we follow Gods commandments the world will become a better place, we will become better people and we will come to know our father in heaven better. Hope this helps you understand why God wants to help us by giving us commandments and guidance.