Is there a table in DB where I can find the API attribute IDs for OOTB attributes of several objects?
Clarity Application
You can find the API attribute ID in the column api_alias, for example on the status report attribute name = overall status, and the api attribute id = overallStatus.
For other you will be able to find in the tables below:
ODF_CUSTOM_ATTRIBUTES
Added column:
API_ALIAS
ODF_OBJECTS
Added columns:
API_ALIAS
IS_API_ENABLED