Computers these days come in different forms for different purposes.
Buying a new computer is not usually a herculean task once you figure out why you need one.
You might need a budget laptop or desktop for basic usage (such as web surfing, emailing etc.), something higher for more serious tasks, maybe even a server if you need to manage other programs and devices or maybe you just need a projector to project videos and presentation onto a larger screen.
A Desktop or Laptop:
First of all, where do you intend to use it? At home, at work or both? Is it going to be stationary or mobile? An answer to this would give you your first advice to getting either a desktop or a laptop?
If you would be using the system in one location with ample space, getting a desktop might seem ideal because it offers more upgrade options should your needs increase, flexible screen size, arrange your keyboard in a way that's ergonomically optimal for you. etc. If your computer system would need to be carried around often then a laptop is the best option as it is portable and ranges from budget o business to meet your computing needs. You can also connect to larger screen if need be when you are at a desk. We have a large variety of desktops and laptops ranging from high end to low end for you to choose from.
There comes a time where you would have the need to manage other programs or devices independently, at that point you need a server. A server is basically a computer dedicated to provide different services to other computers. So you can create a server out of a workstation or a desktop if need be. Although nothing beats a dedicated server if you are planning for the future as they can be upgraded overtime to meet your needs even if you start small.