2. Create database

RDS - Databases - Create database

Select MariaDB and a version. And I chose free tier.

Enter basic information as you want.

DB instance identifier is not database name inside DB. I will enter database name below. A username and password will be used when I connect to the DB.

I created new security group for this DB.

I chose a specific AZ where the EC2 will be. If they reside in different AZ, it will cost network transfer fee between AZ.

I entered initial databse name which will be used to connect DB.

I chose the custom DB parameter group that I made in previous step.

Though I chose free tier, it still shows estimated price. But the free tier will be applied if the condition is met.

Click create.