The default VPC will work fine for this example. Once you are comfortable with creating databases, you may want to consider a VPC containing private subnets that you can use to segment your database away from the internet and other resources (in the style of a three-tier application). Either way, you'll need to note down the following:
- The ID of the VPC
- The CIDR range of the VPC
- The IDs of at least two subnets in your VPC—these subnets need to be in different AZs, for example, us-east-1a and us-east-1b