You can always draft a holographic will or even request a mobile notary that could authentic your signature/capacity. You could also confirm your wishes with a video recording of your wishes that could be to your family members and beneficiaries. I would consult with a local estate planning attorney in your area to discus this matter.

I agree with the previous answers. A holographic will is a good option. However, the requirements for validity are very technical. Many attorney's are still open during COVID shutdowns and are able to consult with you via email, phone, or video conference. Documents can be emailed or mailed. You should also consider implementing Durable Powers of Attorney for Finance and Health Care to appoint an agent to handle your affairs if you become incapacitated. Consulting with an attorney and having documents professionally drafted is the safest option.

Two options:
1. create valid holographic will yourself;
2. retain attorney to work with you to create valid estate plan
Holographic wills are wills that are handwritten and signed by the testator. In California, if the dispositive provisions of the will are written in the testator's handwriting, and signed and dated by the testator who is at least 18 years old and of sound mind, then the will is valid.
Link further explains:
https://leginfo.legislature.ca.gov/faces/codes_displayText.xhtml?lawCode=PROB&division=6.&title=&part=1.&chapter=2.&article=

In addition to all the correct and valid information provided by my colleagues, I would strongly suggest you contact a CA estate planning attorney. They will be able to walk you through the process while you are quarantined and, in many cases, be able to meet with you virtually to answer questions and even draft documents.

As a secondary issue, once we're past this, you should absolutely have everything you've done redone by a competent estate planning attorney. If the worst happens, a holographic will may be your best be, but once this has passed and we're able to go out again, meet with an attorney to have you plan properly drafted.

A holographic can be created which does not require witnesses. However, there are very specific requirements including that all of the terms must be in your handwriting, it must be signed by you, and it should be dated. You should consult with an attorney to discuss what would be necessary to ensure that the will would be valid and that it will have the results that you intend. You should also consult with an attorney to discuss other estate planning options that can help to protect yourself if you become incapacitated, and that may help keep your estate out of the probate court. Some of these other options are possible even given the limitations of quarantine and social distancing.

Your best path here is, as the others have said, a holographic will. You simply need to take out a sheet of paper and write down in your own handwriting (do not type it) where you want your assets to go and who you want to be in charge of your affairs (ie who is going to serve as administrator of your estate) after you pass. You need not date it, but it is a good idea that you do in case you do another will later, so everyone knows which will came later and is the operative one. An alternative would be to use a virtual estate planning firm, who can walk you through how they can help you virtually. Wishing you a speedy recovery.

You could draft a holographic will. https://leginfo.legislature.ca.gov/faces/codes_displayText.xhtml?lawCode=PROB&division=6.&title=&part=1.&chapter=2.&article=

There is something called a "holographic will". The three requirements are 1) It must be dated, 2) it must be signed by you (alone, witnesses not necessary) and 3) it must all be in your own handwriting. I will let you do an internet search on that type of will. Last, make sure someone you trust knows where to find your will.