Get Ubuntu for a very simple one.
Well let's begin at the beginning. Linux is a
Kernel one of the best that is, and with this Kernel you can make an operating system. Due to the fact that linux used to be used mostly by professional, it is most useful when you know your way around a computer correctly. In recent years, a lot have been made to make it accessible to anybody. Ubuntu achieved that quite well, the migration from windows to ubuntu being about as simple than from windows to macos.
As for using Linux, the advantages are that you have the hand over your whole operating system, multiuser is easy and safe, you have a library of free software that allow you to do virtually any kind of works, the console is very well designed and easily customizable, the community is helpful, and there the whole "free software activism" if you're interested.
The downside is that there are few games and that you may have trouble with the newest technology, because the community have to make drivers for them (thought I never ran into such problem myself).
Of course it all depend of your field of working. If you're web illustrator, the free software dedicated to the field are very good, but the prevalence of Photoshop and 3Dmax make that your company will most likely use them, so Linux alone won't make it. If you're network engineer, then you must know Linux. Period.
Also virus don't work on Linux, but other malware can. Even Java virus so far don't work. You have to install them yourself.