Your wordpress blog visual appearance depends on the theme you select in your blog admin panel (Appearance > Themes).
By Default, the wordpress barebone CMS ships with two themes , Classic and Default, which are pretty basic in terms of layout and visual appeal.
You can download, install and activate a theme that best fits your industry. There are an unlimited numbers of themes you can find on the worldwide web. Some themes are free to download and use.
However if you want a premium design theme you can either purchase one for a fair price or hire a web designer/developer to create a custom theme for you.
Once you have a theme selected/designed and ready, you install it alongside with other default themes then upload it to your server. As soon as you log into your blog admin panel, you can go yo Appearance > Themes to see you new theme in the list of available theme for you to choose and activate.
Bear in mind no matter what theme you choose, it might still need some tweaking such as making your wordpress theme widgets ready, adjusting some CSS rules one the content start pouring in and so on.
You web developer might need to go inside the PHP code to make some adjustments for the active plugins output to fall in the right places.
A knowledge of HTML, CSS, PHP and Javascript is sometimes necessary to get to the final result that is having your new theme working smoothly.
