Update:
The purpose of this reply is to let the group know what has happened since my initial entry. Since then, I have updated both my iPhone 6 plus and my iPad Air 2 to IOS 10.1.1.
I am retired and live on a strict budget. Common sense dictates that technological redundancy is something I cannot afford; therefore, I do not own a pc. The above serve adequately as my home computers.
1. I have received spam messages to my iCloud calendar. The first was from Rayban and, the second dated 11.25.16, from UGG whatever-that-is.
Both messages appear to have been sent from the same sender. (See message 11.05.16)
I assume that this happened because, due to my own stupidity, I declined the first message which opened my own personal hellgate.
2. I am not and have not been receiving messages in Photos. I have never set up iCloud Photo Sharing because I do not know what it is and I do not seem to be missing out on anything by not using it. I assume that this is the reason I am not bothered by spam in iCloud Photos..
3. RE: Calendars. I followed the instructions for creating and deleting a Spam Calendar.
4. Then, I changed my iCloud Calendar settings thus:
I had to download Google Chrome to my iPad in order to log on to the desktop version of icloud.com and to follow the directions in the photo below: