My doggie is around 2 yrs now, just truned two, But she has behaviour issues!?

Classes are a good idea. You have never been taught how to train your dog and you will learn as much as the dog will. In my area it runs $80 - 110 for six of the one hour group classes depending on where you take them. It may be different in your area. It will make you take the time to work with the dog and the more you practice at home between classes, the better you will do. Invest in the dog- the payback will be a well trained dog you don't mind taking places.