I am creating a website, that includes WP Blog. I did want to use a theme for the blog plus customize that theme. the WP Blog uploaded to server is a simple one. how do I change this, my website has its own front page etc, just using WordPress for a blog
Are you wanting to install WordPress on your existing server that your main website is hosted on? If so, the fine folks over at WordPress.org forums would be able to help you out with that. You may also want to look through the documentation at WordPress.org.
Another option would be to host your blog here at WordPress.com and then you can link to it from your main site. If you wished, you could map a subdomain of your site (blog.mysite.com) to your blog here. One of the main benefits of having it hosted here at WordPress.com is that you never have to worry about updates, maintenance or backups. All of that is done for you by our staff.