Oxnard is in Ventura County
Oxnard sits in Ventura County, and California's workers' compensation system applies there exactly as it does across the state. It is a state system, not a city one, so the same rights and the same deadlines follow you between jobs and between counties.
Immigration status does not decide coverage
Here is the direct answer: California workers' compensation covers employees who are hurt on the job regardless of immigration status. The steps after an injury are the same either way. Report it to your employer, ask for a claim form, and get medical care, telling the provider that the injury happened at work.
What to do first
Report the injury to your employer and ask for a claim form. Do it in writing if you can, even briefly, so the date is recorded. Then get medical care and tell the provider that the injury happened at work — those words are what separate a work-injury visit from an ordinary one in the records. Keep copies of everything you sign, and write down the names of the people you spoke to.
The two deadlines, in general terms
A work injury should generally be reported to your employer within thirty days, and a workers' compensation claim generally has to be filed within one year. Both are general rules with exceptions, and the starting date is not always the day something hurt for the first time. If your dates are close to either line, that is a reason to ask sooner rather than later.
How our office handles Oxnard cases
Our office is in Palmdale; we do not have an office in Oxnard, and we would rather say so than let a map suggest otherwise. Ventura County clients are served by phone, text, and video, and we meet in Palmdale by appointment when an in-person conversation is what you want. The whole firm works in English and Spanish, so nothing has to be explained twice through a family member. An accepted claim is worth reviewing too: insurers provide the minimum they are required to provide, and a free look at your file can turn up benefits you are entitled to but are not receiving. The case evaluation is free, you pay nothing up front, and attorney fees in a California workers' compensation case must be approved by a workers' compensation judge.