Once programs are installed they are hard to move to a different drive without uninstalling and reinstalling - there are programs that will do this but they are costly.
What you can do is move things like your "User folder" which will contain all your downloads picture and videos to the HDD. see here
You can use programs like CCleaner to get rid of junk files and delete all but the last restore point to clear more space on the SSD.
When you Install new programs always click on "custom install " there you can browse or create a folder to where you want the program saved, instead of it always installing to the C:\Program files folder d