Stop brush from using clipboard

[spaghet]

I'm very new to gimp - but a pro at photoshop...trying to make the switch since adobe switched to stupid monthly payments...
I'm trying to simply paint with the brush but for some reason it doesn't use a solid color but instead paints using what's on my clipboard. So when I clip the brush my clipboard image suddenly pastes & I keep clicking it- over & again tons of my clipboard image as if it were a paint color. What is this? The same thing happens when I try to use pencil...

[Ofnuts]

This is because you have the brush set to "clipboard" (which is the first in the list). Just select another brush. And FWIW this can also happen for the pattern image.