Buying new computers, particularly laptops, can be a bit of a challenge for Linux users. Sure, you can just go buy any random computer, but you are not guaranteed compatibility. Yes, all the essential parts will almost certainly work, but you never know for sure without doing some research. The best option at the moment is probably to buy a computer from Dell, System76, or another vendor that offers your favorite distribution pre-installed. the problem is, that leaves you with one major name and a handful of decent smaller vendors.