Is there a way to test and debug DAGs from a local device to Composer Cloud?

You are able to test a single instance in a local environment and see the log output; viewing the output enables you to check for syntax errors and task errors that might occur, but note that testing in a local environment does not check dependencies or communication status to the database.

I would recommend you to put the DAGs in a data/test folder in your test environment and follow this guide that Google provides.