That you're not a pro is not a problem, we're here to help out anyway ;)
This is quite clearly announced actually. Only WIN7 and 8 can update to WIN10 TP, all earlier OS version must do a clean install. SO you need to boot from the ISO by burning a DVD or a bootable USB
You can use the
Microsoft USB/DVD tool to create a USB stick you can boot from or you can use a tool like
Rufus.. The latter will be required if you want to create an UEFI bootable USB..
This will erase all data on the disc you install to so make sure you either use a separate disc of have backups.