Programmatic User Account Creation for EC2 and EFS?

I'm using an EFS with my EC2 Linux instance to create writable per-user subdirectories. This entails creating the user, the subdirectory, and then mounting the user's home directory to the subdirectory.

Is it possible to create a script to streamline this process? And if so, could I extend it to include some other automated tasks, such as:

1. Copying default contents to the user's newly created subdirectory?
2. Initiate a script for creating a MySQL user and table?

It'd love to be able to to provide the user's username and password and have the rest of the setup automated.

Thanks!