Creating childtheme using Mamp, 500 Internal Server Error

Hi There,

I am using WordPress locally (using Mamp) in the process of building my first child theme. I have gotten the child theme up and running containing only my css stylesheet. As soon as I start adding other files like the header.php, functions.php I get an 500 internal server error.

I have tried deactivating and reactivating the child theme, same thing happens. As soon as I remove the files, everything is back to working like normal.

I have edited the css and it is working properly. Would anyone know why I get and error when adding the other files? Any help would be appreciated! Thank you so much!