If you want to do a new install of Windows on the SSD then you need to have an install disk for Windows that is either on a DVD or USB drive. Google how to install Windows 10, there are lots of good guides. But basically you go to a Microsoft site, click a download and follow the prompts. It will create the disk for you that you then boot from and then tell it where to install Windows. You will want to disconnect or disable the other drive before you do this!
If you want to clone your current drive to the SSD in order to keep using the system the way it is but with much faster performance then you can connect the SSD to the computer (using USB enclosure or connect to a spare power and SATA port inside), clone the existing drive using...