This blog lists the sequences of AWS services you have to setup for a scalable system. It is not required to setup in this sequence, but I found it is one of straight forward and the easiest way.

AWS Certificate Manger

Create SSL certificate for your system URL and import it. You can reimport for update.

EC2 – Key Pairs & Security Groups

Create key pair to use. EC2->Network & Security -> Key Pairs

The user name of Ubuntu is Ubuntu not like other EC2 instances.

Create Security Group for CE2 instances(Web Server) and RDS(DB Server)

Dev Server

Launch Template

Auto Scaling Groups

Load Balancers

RDS

AWS WAF – Web ACLs

Make if sure to set IP sets if it has in-bound and/or out-bound API call to call/listen.