Why open Thunderbird at all? Don;t open it and it will not ever do anything because it is not running.

Uninstall it, again it will not do anything.

I amafraid that the Thunderbird email program will take up too much memory on my computer, I receive a lot of pictures and I do not have extra memory. How does it make sense to have 2 email programs receiving the same emails? Like I said I want to disable or uninstall Thunderbird and I do not know how to do that?

You are kidding right?

If you want to know how to uninstall a program ask Microsoft it is their operating system. https://support.microsoft.com/en-us/instantanswers/ce7ba88b-4e95-4354-b807-35732db36c4d/repair-or-remove-programs

Please ask someone near you who knows more about computers, to uninstall Thunderbird for you.

Since you don't know how to uninstall a program, I fear that your computer skills and understanding are not enough to follow instructions I can give.