Looking at the specs on the Asus website it looks as I thought and your particular laptop is a ‘Basic’ budget machine intended for school* or very light home use.
It would normally come with Windows 11 S-mode installed, so you can only get applications from the Microsoft Store.
(I assume you got CCleaner from the MS Store).
It has 64 GB of eMMC storage, but the user can only see about 57 or 58 GB of that.
eMMC is soldered in and so you can’t swap it for more storage.
*When used for school all the work that the student does is uploaded onto the schools servers, so the laptop itself doesn’t need much storage, just about enough for homework.
(It also prevents the kids from putting games etc. on it).
I can suggest 4 things:
1: If you can afford it then get a better spec laptop with at least a 250 GB NVME drive.
2: If you want to keep using that laptop then get an external drive that plugs into a USB port.
Then move and keep all your own files on that, leaving the internal eMMC just for Windows itself to use.
If you have a techie friend, or a local computer shop they can fairly easily set it up so that whenever you save anything it goes onto the second, external, drive rather than the small internal storage.
3: instead of an external drive use OneDrive or other cloud storage to save your files to.
(A bit like school students use the school server).
4: A bit more technical, but as I said above junk Windows and put Linux or Chrome OS Flex on it.
(Chrome OS Flex saves all your files to the cloud storage in your google account).
In the end as I said at the start.
64 GB is not really sufficient to run Windows 10 or 11 on and you are always going to struggle for storage space.
Using CCleaner regularly to clear the junk, browser caches, etc will help, but I’m afraid that you will always be fighting a losing battle with Windows 11 on that little storage space.