When you view your blog front, you see your latest post first: that's the way all blogs work. Same thing when you click on a category tab: you'll see the posts filed under that category, latest one first.
If you don't like that, you can set a static page as your front, and you'll need to create an index page with links to your articles arranged in any order you like. The front page can be the index page itself, or an intro page.
The disadvantage is that category pages are updated automatically, while your index page will have to be updated manually each time you publish a new article.
If you settle for that, you can even do away with posts and categories, and publish your articles as static pages instead of posts. Static pages aren't arranged chronologically (in most themes they don't even display a date stamp).