The Welcome Center is a great starting point for prospective, new and current students. Your New Hire letter will instruct you how to enroll into your benefits online.Log in to Insite to get your registration date and add the classes you want to your schedule during your registration period. 3. Patients who have Contra Costa Health Plan (CCHP) can also call the CCHP Advice Nurse at. 1-877-661-6230 option 1. The following documents in the Welcome Packet will include: Welcome Letter, Child Care Agreement(s), the Participation. Medi-Cal offers no-cost and low-cost health insurance to those individuals living in California that meet the eligibility requirements. Welcome to the Housing Authority of the County of Contra Costa. The following documents in the Welcome Packet will include: Welcome Letter, Child Care Agreement(s), the Participation. The Welcome Center is a great starting point for prospective, new and current students.