how to play the middle game ?

i dont have any idea about playing the middle game in the openig i develop the minoe

r pieces and after that i dont know what to do next can anyone help me ??

After developing, you should start improving your pieces and look for a plan. I have made many videos of the topic: http://www.tigerlilov.com/middlegame-lectures

I'm amazed at how long I've played chess and how many games I've played BEFORE I ever started trying to plan.  What a waste of all those years!