Installing Windows 10 should be pretty straight forward. Just make sure you have another computer with an internet connection that you can use to download and create the bootable flash drive with.

Check out the general steps below. The video will go into more details.

Step 1:

Buy an activation key (Microsoft, Amazon, Kinguin)
Have at least a 4GB Flash Drive (8GB is recommended) they're pretty cheap now a days.

Step 2:

Download the Windows 10 OS (Download the installation media tool)

Step 3:

When prompted by the Windows Installation Media Tool, Choose "Create Installation Media"

Step 4:

Boot up your new computer and go into the BIOS. Go to Settings>Boot>Boot Option # 1>Select the USB Drive that you plug in.

Step 5:

Just incase, go ahead and go to the manufacturer of your motherboard and graphics card and make sure your drivers are up to date.