Access denied errors everywhere in my AWS IAM account

When you mentioned IAM account, do you mean another IAM user other than root user or AWS account? You are getting this error, while using that IAM user or root user?

I assume this error is not coming for root user and you are seeing all these errors when logged in through another IAM user.

Since you mentioned, this is for personal usage and you are managing this, I'd suggest you to login as root user and if newly created IAM user is supposed to be admin, then add AdministratorAccess policy to this IAM user.

1. Go to IAM console
2. Click on Users
3. Select that IAM user
4. Add Permissions(right side of the screen) -> Select Add permissions from dropdown
5. In next screen, select Attach policies directly
6. Type AdministratorAccess in the search and add it.

Log out and log back in with that new IAM user. This error would go away.

Additionally I would suggest you to make sure that there is no SCP at OU level, which might deny other user access(less likely in your case, as you just set it up).

If you are seeing these errors for root user, then did you try logging out and log back in if this account is recently provisioned.

For more details, refer Policies and permissions in IAM.

Hope this helps.

Comment here if you have additional questions, happy to help.

Abhishek