New user - several immediate errors

I am not sure what has gone wrong. I do have a couple of suggestions for your safety. First, do not use the root account to administer your account. Make sure your password is secure. Spend some time to make a secondary admin user and turn on Mult-Factor Authentication (MFA). This is for your safety. You certainly don't want someone else in your account performing actions that would cost you money.

MFA

https://docs.aws.amazon.com/accounts/latest/reference/root-user-mfa.html

Guidance from AWS

https://docs.aws.amazon.com/prescriptive-guidance/latest/aws-startup-security-baseline/controls-acct.html

If you are downloading resources, like CloudFormation templates, from the web and running them, it may be necessary to understand them before execution. You can also open the cloudformation service and review any stacks that have been created.

ECS stands for Elastic Container Service. This is a very advanced feature for running large workloads. AppRegistry information can be found here: https://docs.aws.amazon.com/servicecatalog/latest/arguide/intro-app-registry.html Cloudformation stacks are the building blocks of AWS. They house all of the assets to be used on AWS.

Also, for web storage, you'll likely want to use S3 which is also called a S3 bucket. This is most likely the best approach for you.

Hope this helps, if it does please accept this answer.