Well, let me give you some ideas. I have mentioned some of this elsewhere, and I will try and link back to it later. It’s hard to know where to start giving advice when you don’t know the skill level and gear of the person you’re giving advice to, but I’ll make some assumptions and hope for the best.
The first thing you need is a PC you want to put Linux on. Linux is supported by people donating their time and so that means drivers and support are not always 100%, or that they lag more commercial endeavours, but these days you can have pretty good luck if your PC is fairly commodity. (If you have weird WiFi/network cards you might have problems, but you’ll have to try and find out, I guess.) If you just want to play, to see how Linux would feel, without “sacrificing” your PC, you can possibly use a virtual machine if your PC is powerful enough. Check out VirtualBox from Oracle for a good, free, virtual machine host.
If you’re going to install it onto a spare PC, make sure you backup anything on it, just in case. There are some installers for Linux out there that will set up dual boot so you can keep your current OS, but that can lead to tricky problems with updating the other OS (Windows 10 has had issues with this, for example.) If you have the hardware, better to dedicate it to the effort to have one less thing to go wrong.
So now you need to figure out how to get that Linux installed on the PC. To do that, you’re going to need to be able to boot from a Linux image. Now is the time to see how that works. If you’re cool poking around in your BIOS/UEFI then you can look there for boot order or boot utilities. Many machines show a message when they’re booting about pressing a key for the boot manager… like F12 or F8 or something. This is also the point where you can look to see if you can boot from a USB stick if you don’t have a DVDROM drive to boot off of.
Most distributions come in a ISO format… which is basically an image of a CD or DVD. If you have a machine that can boot off a DVD, then you can download the ISO and burn it onto a CD or DVD (depending on size) and boot from it. If you are on Windows and need a tool to burn an ISO, I would recommend ImgBurn https://www.imgburn.com/ as a nice light tool.
And this is about as much as I can offer. At this point you have chosen your distribution, and downloaded the ISO and burned it to a bootable media. Now you boot it, and hopefully follow simple instructions to install it. Some of them may ask you to set a password for “root”.
In Unix root is the admin account. It is all powerful. Make sure you choose a good secure password, and don’t forget it… write down if you have to. In general you should not run day to day as root. You should be in a user account, and you will elevate to the root user when it is necessary. (Mostly for maintenance and installing programs.)
Many other Linux distros have disabled the root account for direct logins. In that case, it will ask for your user account name and password, and it will make this user account able to do admin. It does this by putting your account in a list known as the sudoers list. The sudo command is a command that lets you “set user and do” commands from the command line. So if you needed to run command “foo” as root, you would do “sudo foo”. It will prompt you for YOUR password (to confirm you’re still at the keyboard, and some hacker hasn’t just sat down when you got up to get coffee) and change to user root and run the foo command.
That should be enough to get you going. Have fun learning and exploring. I bet you’ll feel pretty comfortable pretty quick, and you can always ask back here if you get stuck.