If you are feeling ready to make the switch, by all means, do it!
Linux, in my personal experience, has improved leaps and bounds in the past couple of years alone. There are many bootable Linux distros, and I'd stick with the more mainstream ones if you're just starting out. (I've used it for several years myself, since 2013-ish.)
If you're looking for a distro that can be run purely off of a USB drive, try something lightweight like Puppy Linux. It's designed to run off bootable USB drives and similar.
If your computer (motherboard) has UEFI firmware, be aware you may encounter issues with Secure Boot. (Microsoft forces manufacturers to include this malware that refuses to boot pretty much all non-Windows operating systems).
Ubuntu is the most well-known and well-supported distribution. For less powerful machines, there are versions like Kubuntu or Lubuntu, and other spinoffs like Linux Mint. All of these distributions are based off Debian, but I don't think you should start with Debian.
If you're planning on installing Linux to your hard drive, I highly recommend a configuration called Dual Boot. When configured properly, it will allow you to switch between Linux and Windows when you start your computer, enabling a smooth transition (and allowing you to run some pesky programs that don't run on Linux.)
I run Linux entirely on my computers (a distribution called Arch Linux, which, while lightweight and advanced, is difficult to install and use for a beginner) and I'm able to run several Windows-only programs from within Linux with a tool such as WINE. These can be annoying to get working, however, and I suggest you stick with Dual Boot until you are more experienced.
Don't get discouraged, Linux is very, very easy to use once you have a little experience -- if you are capable of reading and carefully following directions, it should be fairly straightforward. As you learn more, you'll be able to do things much, much faster than you would just using Windows, and in general the experience is much nicer.