my first blog

Looks nice. But: You’re using a layout with fixed widths, so with a browser window actually wide enough to display the page reasonably but not wide enough for your specified widths one still has a horizontal scrollbar. You should either use relative widths for the columns or just a max-width.
And additionally there’s something I’ve never seen before: Each line in the actual posts seems to be an individual paragraph, so that they have a quite ragged look. Do you hit return on the end of each line in your edit form? Don’t do that, hit return just for new paragraphs, so the browser can figure out linebreaks within paragraphs on its own.