Hi There @debbiepacker
To further narrow down your issue, please install the following plugin (https://wordpress.org/plugins/wp-serverinfo/) activate it and then head over to Dashboard -> WP-Serverinfo section.
Then check the following server configurations.
PHP Version - We recommend PHP v5.6.x or higher to avoid incompatibility issues. If you see a version below 5.6, you can contact your hosting provider and ask them to update it.
PHP Memory Limit - On the first reply, @Prasant mentioned on how to increase memory limit. If you have done it correctly, you should see your current memory limit as 512MiB. Some hosting providers does not allow to change these values. In that case, you will need to contact your hosting provider.
PHP max script execution time - We recommend the value of 120 or higher (300). Here's how to increase that value (https://www.simplified.guide/php/increase-max-execution-time).
Usually that should resolve your issue. if you're still experiencing the same issue, please provide us with your WordPress login credentials in a secure note to check your issue further.