It would be a great experience for you to build a Linux server since it would make you aware of what goes into running and managing the Linux servers. You would get to learn about not just the software end but the hardware end of the system. You can get a basic idea here as a start.
To begin with, it is imperative that you assemble the right hardware according to your requirement. While looking for the hardware assembly, you should the points such as performance, size of the hardware components, storage capabilities, cooling mechanisms, cost, and compatibility. While deciding on the storage, it is advisable to go for the SSD to ensure better performance. You would also have to decide on the type of internet connection and if you are using a router then you should forward the port 80 to the webserver.
On the software end, make sure to go for an operating system which suits your requirement in the best possible way. You’d have to install web server software like Apache. If you’re a beginner, you can also use the GUIs which are available for Linux to make your job easier.