Hi Kristena
1.
3rd Party Applications:
Some 3rd party application installers will allow you to choose an alternate install location, for those, create a Program Files folder on your D Drive and install those into their own sub-folder of that folder
Other 3rd party application installers will not allow you to choose an installation folder, for those, there is nothing you can do . . .
2.
Windows Apps or Windows Store Downloads:
Open the Settings App (Gear icon on your Start Menu)
Go to System - Storage - 'Change where new content is saved'
Ate the top, from the 'New Apps will save to' drop down, choose your other drive (HDD)
That's It!