Hi
If your C:\ drive is a full hard drive and has no other partitions on it, other than the normal ones that Windows creates as part of the install then there's not much that you can do. It's size is what it is.
What you can do is move stuff to Drive D:\ i.e. Photos, Music, Documents etc.
You can even uninstall and reinstall your software and move it to D:\ in the process.
I don't install any of my software to drive C:\, when Installing anything I change the C:\ to D:\ Then I let it create a new folder, as a result my C:\ drive only uses about 75 GB of disk space.
It will create a new Program Files and Program Files (x86) folder just like the ones on C:\ as long as you change only the C and use the default address otherwise.
You can also move the Users folder to another drive (I've never done this myself) on my computer the Users folder uses half the space on my C:\ drive.
Here's an article about how to do it.
I didn't read all of this, but it looks like it explains everything.
Users Folder - Move Location in Windows 10
Note that it says you shouldn't move software, that's why I uninstall and reinstall it to move it to D:\.
Beyond that there isn't much that you can do.
Mike