There are a bunch of resources for images if you loo here https://devdocs.prestashop-project.org/8/webservice/reference/#available-resources
You can access them with https://example.com/api/{resource_key}
This is enabled already in the .htaccess created upon install but you need to have it server side enabled too e.g. mod_deflate, mod_gzip enabled as apache module
Please open a new topic for your issue do not use another's.
There is a quite explanatory module creation documentation at https://devdocs.prestashop-project.org/
It is clear.. ask your provider to switch PHP to at least 7.2
After that, be prepared to have issues with the some third party modules if they are not PHP7.2 compatible case in which contact the developers and ask for newer versions.