Hi Nelly, I have just looked at and thru your site for about 5-10 minutes. I don't know where to begin. Lateron tonight when I have some time I will take a look again and see if I can lead you into the right direction.
The site is not good. Structurally it violates too many search engine rules to really count. Why don't you just get a blog onto your site and start creating content there. That may be the easiest and cheapest way for you, otherwise I could only recommend hiring a professional to redo your site for you. Sorry
Mike