This is the “white screen of death” error. Its likely that one or more of your code files has a PHP syntax error. It could be just one character in the wrong place. That’s enough to stop PHP from running.
If you have edited any files, particularly functions.php, check and correct the syntax of the code using this service:
https://phpcodechecker.com/
If you don’t find the error, the method is to reduce your install to the simplist possible. Temporarily deactivate all other plugins and switch to the default theme, and test. If the shop page shows now, put software elements back one-by-one and check. You are trying to identify the plugin that is causing the problem.
If you can’t find the plugin that is faulty, you may need to use ftp or your host’s file manage software to upload fresh copies of the files. Delete the existing files first, don’t overwrite. Don’t delete plugins in the Dashboard because this can result in loss of settings.
Take a backup before debugging.