how can i stop my dog barking and pulling on lead to get to other dogs all she wants to do is play but it is becoming a right pain and embarrassment please help

You should try joining a training class these are really good for teaching your dog to behave in a controlled mannor and is also good for socialisation. The 'British Assosiation Of German Sheperd Dogs' is brilliant and they have training clubs all over the place do a google search for them.