You don't say what browser you're using so it is hard to be specific.
First, if you have a specific site you want to have as your home page, navigate to it, then do the steps below. There is usually a button to click that is labeled "Use current page" or something like that.
Using M$ Internet Explorer, click on Internet Options then the General Tab. You can change the setting in the top window there.
Using Firefox, select Tools/Options/General, same thing.
Chrome and Opera will be similar.