All federal courthouses in the Sacramento-based Eastern District of California have been ordered close to the public because of the ongoing coronavirus crisis and trials have been continued to May 1.

An order signed Wednesday by Chief U.S. District Judge Kimberly J. Mueller orders hearings and other matters to be held by telephone or videoconference unless an exception is made by a judge for matters that do not require the presence of a jury.
Same is true in state courts.

Yes, you can file new cases online but they won't be served until the courts re-open and that probably won't happen on May 1st.