Database - Yes, install a local database server, create a database schema, create a relevant user instead of the default user, execute the wM database scripts for the components you want and then point your local IS to the database. Read the installation documentation for more guidance.
Now, if you’re installing the IS from scratch, you can setup the database first as I mentioned above, and then pass the connection info and credentials directly during the installation of the IS - no manual updates to JDBC Pools or a restart are required.
Also, depending on what you want to do, you can just use the Embedded database that ships with the IS by default - you may not need an RDBMS.
JDBC Adapter - As for JDBC, you must install a component named “webMethods Adapter for JDBC” and you’ll have the package installed and loaded for you. Don’t import the package manually from your development instance.