Can you please tell me how is Apple TV, Podcast, and Chess necessary for the functioning for MacBook? I have lesser deta and more of unnecessary programs that I never use but are taking space and not letting me use iMovie!!!

It's not that those apps are necessary. Just that those apps come as part of macOS. And for a while now, Apple has made it such that things that come with a fresh install of macOS cannot be removed. The intention behind this is so that you don't inadvertently damage the installation of macOS, thereby eliminating the danger of a corrupt or damaged installation of macOS. I agree that you ought to be able to nix stock apps that you don't need anymore. But, (a) those apps don't take up that much space and (b) if you are lacking space to use iMovie, you probably have something else taking up a lot of space that you can get rid of.

What does Chess have to do with using iMovie? Really?!!! Can you elaborate on that?

If your problem is space because you want to edit video, removing two or three applications like these (even if you could) would not help. Chess takes up... about 7MB. That is less than a few seconds of video. The three applications you mention take up just over 100MB. For any meaningful video work we're talking several GB, and that is just for starters.

Video files take up a LOT of space.

If you are serious about doing some video work, get yourself a nice external SSD. You are going to need that space.

You cannot delete apps that come pre-installed with macOS.