What you mean, I believe, is that you want the 1TB unit to be the default place where all your user data files are stored. To do that, you probably need to do two things.
1. In Windows, you can specify where certain key folders are located. These especially include folders like My Documents, My Pictures, etc. You need to tell Windows that you want those placed on the 1TB drive, not on the C: drive (the usual default).
2. Within most major application software (e.g., Word, Excel, Photoshop, etc.) there is always a place where you can specify the default locations for all the files it uses and stores. AFTER you have set up the Windows defaults above, go into the app software and set their default file locations to places on the 1 TB unit.
A further thing you may want: in future, whenever you are installing any app software, you must specify where to install it. Usually it will default to installing on your C: drive, and let you change that to another location, like on your 1TB unit. (Some software insists only on the C: drive, but not most.)
If you have app software already installed on your C: drive (the SSD) and don't want it there, you cannot just copy it over to the other HDD. Installing app software also establishes a bunch of entries in the Windows Registry about where everything is. So, if you want Word to be on the D: drive instead, you may have to Un-Install it from the C: drive, then re-Install it on D:.