1. get your perferred iso
2. do a checksum if available (basecally check the signature of the original file with yours, the checksum often is available on the website)
3. get beleana etcher or i think rufus can also do linux isos but i’n not shure
4. get an usb stick with min 4gb
5. flash iso onto usb stick
6. stick usb stick into perferred pc
7. boot onot that usb stick (for my motherboard it’s F10 but that can be different for you)
8. boot into the live iso and the installer should pop up
9. read the instructions of the installer carefully
10. you are done enjoy your new os

although i would recommend playing around with different distros in a vm to see waht you like and if all your needed software is available