If you are unfamiliar with the difference between a keystore and a truststore, check out this article.
In this example, a keystore named myKeystore is created, and the keystore is using the DefaultKeystore.p12 file. Keystore files can be created using the keytool command. You may want to also view the keys in a keystore, to ensure the keys are still valid and have not expired.
After creating a new keystore, you will probably want to update your SSL default keystore to use your new keystore.