I cannot delete the stocks app or Chess app from my Mac Book Air. I have never used either and need additional space.

as already stated, you cannot. but deleting most apps would not clear up much storage at all. the chess app is only 4.7 MB in size and stocks is only 2.7 MB.

however, if you are running low on space, you can purchase an external HDD or SSD of sufficient capacity and move your larger files (videos, pictures, documents, etc...) to it. once they are on the EHD, you can simply erase the same files from your internal drive. and, if it's just going to be used for storage, you can use an HDD and save a few bucks over the cost of an SSD. FWIW, i personally keep very little on my internal drive.

also, you may want to read these two articles:

Optimize storage space on your Mac

How to free up storage space on your Mac

additionally, you want to keep ~ 20% of your local drive as free space for proper operation of macOS.

[EDITED]

Wow, no one knows how to google “Disabling SIP” here?

No Chess.app here. 😉

Even if you could, the additional space added back will be miniscule. You clear meaningful space on a drive by deleting USER data and only user data. Move it to an external disk is usually a good choice.

Those apps cannot be uninstalled but the space used is inconsequential