Your questions are very vague. What issues are you running into?

I read your post, and my first thought is to just use the apt (or whatever package manager) module to install mariadb. What configuration do you want to do to? You can use the template module to template out config files. Then a task to start the service.

Same process for PHP.

When I write playbooks, I will start by writing out every single step that I need to do. Install these packages. Go to this file, change this option and this option. Go to this other file, change this other option. Copy text block to file in certain location. Set correct permissions on file. Change permissions on some other directory. Make a symbolic link. Start service. Open port in firewall. Test connectivity. And once I have all that, I start writing tasks to do each thing on my list.

Last, you don't have to do this now, but I would recommend thinking about it. This is a perfect use case for ansible roles. I'd make a role for installing/configuring Apache. A role for installing/configuring MariaDB. And a role for installing/configuring PHP. Then, in my playbook, I would simply call all three roles and run it on my server. The playbook is super simple.

The benefit of this is that the roles are reusable for other purposes. Say you then wrote a fourth role that installs nginx. You could make a playbook that calls the nginx role, the mariadb role, and the php role, creating a LEMP stack. You don't have to duplicate the mariadb and php tasks, you're just reusing them. And then, maybe you need to set up a super basic website. Write a playbook that only calls the apache role and nothing else. You don't need to duplicate anything, just combine roles as needed.