Ok, I gave you a chance to back out and admit your incompetence.
So you are a web developer and offer your service for 50$. I am not a web developer and I can offer the same work for as low as making it worth my 5 minutes.
Everyone can install a wordpress theme, anyone can install wordpress plugins, anyone can edit sidebars. Wordpress is designed so every homeless guy with basic computer knowledge can use wordpress.
To put you out of business completely: People, instead of buying from him, let me google for you what you need:

.
The only part you might have issues with, if you are not familiar with it, is installing wordpress on your webserver. If you purchased web hosting, you will most likely have a 1-click installation script that will install and set up wordpress for you. After that, all you need is to download the theme, upload it to the themes folder and apply it in the dashboard.
In case you want to install wordpress on a VPS:
If Windows: Get XAMPP which also has downloadable add-ons that will install wordpress for you. You can also do it the manual way and download wordpress from

, extract it to the root of your web space (this also works on web hosting) and navigate to

and the in wordpress installation with open (you could also install to

, just extract the files to root/wordpress).
If Linux: Here things become a bit tricky because of no GUI. You will need to manually create a MSSQL Database for Wordpress, install a LAMP Stack (basically everything you need to run a website in one package) and, as described above, install wordpress manually. Simple use google to find guides.