bethp1819 :
Thank you for answering the questions, it's a big help! So with the dual storage I guess I save Windows 10 to the SSD and then do you keep your files, etc. on the mechanical drive? Also, you are sure the cheapest option will be able to run rocket league and fortnite smoothly with multiple windows open while streaming? I'm assuming I'll have to buy virus protection on top as well?
I was watching this video about building a PC (https://www.youtube.com/watch?v=OZaFqY8UF6I) and from 17:50 onwards do I need to do this?
Yes, you install Windows to the SSD. Within Steam (or other platform) you can direct where you library is stored. Direct that to the HDD (the D drive, typically).
Cheapest? No. Best value in price/performance, it should be, yes. As I mentioned, you *can* play/stream on an i5 / 1060 (or even a 1050TI etc), but would be far from an optimal experience IMO - although you are looking at relatively light titles.
Paid virus protection is not a necessity. Between free programs like AVG or Avast et al (one, don't use multiples) there should be sufficient protection. Add Malwarebytes for periodic scans and you should be good to go. Of course, if you plan to spend much time on shady areas of the web, or downloading questionable programs etc, then more premium "paid" options may be a worthwhile consideration.
Yes, you'll need to install your drivers. Windows 10 does a decent job of finding them for you, but I would always suggest installing the drivers from Nvidia and motherboard manufacturer directly.
Ideally, download them before you install Windows and do not provide internet access to the system initially upon Windows install.
Have the drivers on a USB flash drive or external HDD. Once Windows is installed, connect the USB/HDD and install all the drivers at that point. Reboot once complete & then connect to the internet. Windows will fill in any "gaps" at that point (along with any Windows updates required).
Also note, create your own installation media here:
https://www.microsoft.com/en-ca/software-download/windows10
You still need to buy a license, but the media it comes with is likely dated. If you install from that retail media, you'll then have to go through a bunch of patches/updates. The tool linkd above will allow you to install the latest version of Windows, patches/updates and all!
As for building a PC, installing drivers etc - I find PaulsHardware's videos to be pretty comprehensive and easy to follow.
How to build:
https://www.youtube.com/watch?v=9zQXFkzZ1Ac
First 5 things to do (test, BIOS, install Windows, install drivers)
https://www.youtube.com/watch?v=LbpqkiaO7q4