@Cesar Marcialās recommendation of a basic project is good too.
You need to get to the point where you're connecting the output/attribute of one resource/module as the input/argument of another (not just typing everything by hand).
Also, if you're trying to build an AWS VPC instead of using the default, use a module like:
https://registry.terraform.io/modules/terraform-aws-modules/vpc/aws/latest -- building all the little pieces individually is tedious.