First of all, you should learn a little bit of patience. There’s lots of people asking for help, but only a few *volunteers* than can help out.
From your description, it sounds like you already have an existing website, but you just want to add WordPress to it. What you should do is – first of all, since you’ve messed up your current installation – remove the current installation. (This also means logging into your host site and deleting your database, then re-create it). Then, upload all of your wordpress files and folders into the folder yoursite.com/wordpress. Then run your installation from there.
After you’ve done that, you can open up your current and existing index page (on the site your running right now), and at the top of that file, put in include('/home/your_user/public_html/wordpress_directory/wp-config.php')
(you want to use the direct path from your server – NOT the URL, and don’t go “relative” because it may get messed up).
Now, on your index page, you can simply include the Loop where you want the “posts” to show up.