What to Save on SSD and HDD? New PC. Change Default File Locations

TLDR: What should be in the HDD storage drive instead of the the SSD boot drive?
What files default location should I be change from SSD to HDD?
And can and should I move the default of locations of these files?
- ProgramData
- AppData
- the (username) file (maybe not necessary)
- Temp
- Public or Public\Cache.Windows
I already changed Program Files, Program Files (x86), Documents, Music, Pictures, Videos, Downloads.

New PC with SSD(500gb) and HDD(2tb). I want to move as much as possible from the SSD to the HDD from the start.

What files should I change the default location of?
I got a new pc with a SSD(500gb) and HDD(2tb) with Windows 10. I am new to this so I just googled everything. SSD is my boot drive and HDD is my storage guide. I want to changed the default locations from the start so I don't have to move files later. I googled and they usually just say move Documents, Music, Pictures, Videos, Downloads.
I have downloaded TreeSize Free.

I changed the Program Files location
I know I'm supposed to install the heavy games and programs to the SSD and the lighter ones to the HDD. I Regedit the program files so that it will the programs will automatically go to the HDD. Because a lot of programs don't ask me where to install.

I just typed it here for convenience. (? and Italics I didn't change)HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
- ?Default
- CommonFilesDir
- CommonFilesDir (X86)
- ?CommonW6432Dir
- ?Device Path
- ?MediaPathUnexpanded
- ProgramFilesDir
- ProgramFilesDir (X86)
- ProgramFilesPath
- ProgramW6432Dir

Can I use Regedit?
I was told not to mess with registry because it will break my Windows on the next update install.I have changed the AppData Files on HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders

Should I just use Symbolic links instead of registry for some?
What should I link? Should I save certain AppData to SSD and others to HDD?

Thank You Very Much