You can actually try them out on your site If you don't like it, you can switch back. After you gain a year or more experience, it will matter less. My company employs experienced Programmers and Webmasters. We Collaborate on a new theme. There are hundreds of new themes released each month. No human, not even a PHP programmer can keep up with them all.

Writing your own custom theme is fairly easy. I suggest checking Youtube or WAs own Marion Black. She has enough experience to steer you in the right direction.

Themes don't usually look the same as they do in their demo when you're picking them. Usually when you download them they are in their basic form and it takes some customizing to make them look like the demo. It may be a matter of just customizing it to make the themes come to life.