so after I physically install my old drives into my new build what would be the steps to take after the power button is turned on? I have only built one computer which is my current pc and do not really have much experience swapping things from a software/program standpoint... if that makes any sense.
Given a new SSD with a new OS on it, and old drive(s) with old OS and applications + games on it..
Idealoly, you copy anything from that old drive to some other location.
Then, you wipe that old drive completely. All partitions.
THen, you can copy the stuff back.
Steam games, for instance...you find the Steamapps folder on the old drive.
Copy that entire thing to some other physical drive.
Wipe the old drive
Copy that SteamApps folder back to the one you just wiped. You can copy it to any folder you like.
Then, in the new Steam client with your new OS, add that location.
Thusly:
Steam games location
In the steam client:
Steam
Settings
Downloads
Steam Library Folders
Add library folder