I have a speech of Zhukov and i want to tell of his career in WWI
You mean you need to give a speech on him, so, schoolwork? In that case, I'd like to simply point you in the right direction to research this. "Stalins General" by Geoffrey Roberts is the best English language biography on Zhukov. Roberts also is the editor for the most recent English edition of Zhukovs memoirs. Get your hands on those and it covers the topic quite well.