How do I remove an arrow that appears on the left side of my iPad screen?

It's not random, it's the multitasking tab. It means you have a an App or window open on the side in slide over mode. Tap on the arrow to bring out the app that is open and slid over.

Tap on the 3 dots at the top of the window, then on the black square to open it completely. Then you can swipe it up to close it normally.

More details here: link-> Use multitasking on your iPad - Apple Support

Mrs-manic wrote:

I don’t like the side arrow. I don’t want a multitasking tab. It’s annoying.

Then close the app that is in slide over mode as explain above. That removes the arrow.

I don’t like the side arrow. I don’t want a multitasking tab. It’s annoying.