If you had insurance coverage at the time of the incident, you likely should quickly notify that insurance company and forward the paperwork to that company.
In general, a defendant has only days to answer a complaint. The time by which an answer must be filed and served should be on the summons. Failure to timely answer may result in the plaintiff asking the court for a default judgment.
If you did not have insurance coverage, you may want to consult an attorney quickly so that an answer can be timely filed and served.
You may also want to check the status of your driver's license. It may have been suspended, especially if you did not provide proof of having insurance coverage.
If you have been summoned to appear in Snohomish County for a court hearing after being involved in a car accident, it is quite possible you are being charged with a criminal traffic charge (for example, Reckless Driving, Hit and Run, or Negligent Driving). If you were drinking, or exhibiting the effects of drugs, you may be being charged with DUI.
My office is based in Everett - if you would like a free consultation, my office is at (425) 322-1076.