You may do better to post your question elsewhere, as this forum is for Forum related issues.
I would suggest the Web design and hosting forum.
Be sure to give as many details as you can. For example, is tis your own web site domain, or are you using some other, pre-determined and 'already created' web site? With your own web site you are in full control, but with a site where you just post a blog, you may have little control.
The white space could be caused by many things, from a blank white image inserted in the html code, to the use of too many line break codes, (eg the (br) element). Tables may also be a source of white space.
If you could post an example of the code you are using, from the (body) element to the first line of your blog text, that may help.
I have had to use curved brackets in this post instead of the usual <http:/> type brackets, as the forum's Jive code reserves some of the triangular bracket elements for its own use. So you will come across the same limitation if you decide to post an example of your html code. Because of that, be sure to use the "Preview Post" button before submitting, as you cannot edit posts in these forums after they have been submitted.
I am trying to post something with html code into a blog. But there is a lot of (like a full screen worth) of white space from the top of the page, to the top of what I am placing in the blog..What is it in the code that will change that white space to less?