I want Opera to stop spying on what I do with FireFox

Opera doesn't do that. At most Opera imports some data from your default browser (what may include cookies) when being installed.

I am automatically signed in to my gmail account that I am signed in with FireFox.

I don't have FF installed here ATM but i've checked with Chrome and couldn't confirm that. Looging in to Gmail on Chrome doesn't automatically logged me in on Opera.

AND EVEN WORSE, THERE IS NO WAY TO DELETE INDIVIDUAL COOKIES.

Please read the forum rules and write on caps.

And yes, you can delete individual cookies. Just go to settings > Privacy and Security > Cookies > All Cookies and site data > search for what you want to delete and delete it.

This link, is written by a very incompetent yet most likely very well paid person

Again, read the forum rules.

This link, is written by a very incompetent yet most likely very well paid person. I am so sick of misleading articles especially when people are paid to do so.

http://www.opera.com/blogs/news/2015/08/how-to-manage-cookies-in-opera/

I am NOT interested in any form of Dirty Hippie Finger Snapping Ukulele Whistling pictures of Plate Of COOKIES with a heart-shaped warm beverage mug.

AND NOWHERE IN THE ARTICLE DOES IT SAY HOW TO DELETE COOKIES, OR EVEN WHERE THEY ARE LOCATED.

APPARENTLY, THERE IS NOT ANY WAY TO DELETE INDIVIDUAL COOKIES.

I HAD TO DELETE EVERY COOKIE WHEN ALL I NEEDED WAS TO DELETE THE COOKIES FROM GOOGLE.

STOP AUTOMATICALLY LOGGING ME INTO WEBSITES THAT I AM LOGGED INTO WITH FIREFOX.

AND FRANKLY, GO BACK TO WHEN OPERA WAS PRESTO BASED.