I have 4 years of experience in the trade (in the last 10 years)

The CSLB requires you to have 4 years of journeyman level experience in the last 10 years. A "journeyman" is defined as an experienced worker who is fully qualified (as opposed to a trainee) and is able to perform the trade without supervision, or one who has completed an apprenticeship program.

I have Social Security Number or ITIN.

The CSLB now accepts ITIN (Individual Tax Id Number), in case you do not have a Social Security Number.