How to clean google email and have more space? Declutter and organize digital messages

 I had many subscriptions which eventually got close to the quota of google.

I have been deleting close to over 30k emails, most are subscriptions. Along the way I unsubscribed from many newsletters. 

Since it still shows 
14.36 GB of 15 GB (95%) used I went to search for help on duckduckgo.com
Here is my findings: (I will share my experience with you) at this point I am gathering information as to how to save space. Besides, I will never look back at those newsletters. Otherwise, I would have added additional storage space.
What is my usage? I found out => 
Google Photos (6.5 GB)
Drive, Gmail, and more (7.9 GB)

My solution: Since I always encourage everyone to have backup of their photos, I started downloading my photos.
Once they are securely backed up in my external hard drive, as well as created another back up, I'll delete those albums.
I also found out videos my friends send are going in the photos albums! Do I really need them? NOOOOO, I have already seen them.
I found out that 
 
My Gmail Trash Bin <= Trash in here is automatically purged after 30 days.
 
Again, I will make another reply to suggest a potential much better way to clean up wasted space.