Bro, open setting --> system --> storage -->
You'll see what's taking up space
Some tips:
Run disk cleanup --> click "clean up system files". Tick mark everything except downloads folder. You can also go to more option, under " system restore and shadow copy" click clean up. Now, go to Disk cleanup tab hit OK button.
Check downloads and document folder for large files (Make sure to enable "view hidden folders" . Some program saves files in default documents folder (which is in C drive)
Press start type %temp% hit enter. Select all and delete
You can go to "C:\Windows\SoftwareDistribution\Download" and delete all the files. These are temp files. You'll find under "Temporary files" storage usage. Windows don't delete those files. But, you can.
Check recycle bin is empty
Click start --> type control panel --> enter --> Go to system --> System protection --> Click configure --> Delete --> Apply --> OK
System restore is disabled by default in windows 10 but if it is enabled you can delete those files.
Run CCleaner