Hello @arbabnaseeb the first question, to find the number of hidden media (or reviews) is quite easy to respond to:
Copy the link to your Maps profile and share it either with a different Google user or open an anonymous session in a browser, paste your link without logging in with your profile (important!). Than open your profile und look for the number of photos and reviews. Those numbers indicate how many have been published (i.e. not hidden). The number with the photo symbol include photos and videos.
Then click on your photo and you the see the numbers, you contributed and you can calculate the difference:
Identifying the hidden media and reviews is more complicated: You need a second user profile and scroll in parallel two browser sessions. One being logged in with your profile, the other with somebody else’. That way you may identify, what you see, but other other one not.
I suggest to read @MortenCopenhagen’s series of articles How to Get In and Out of Trouble: The Main post