I live in California so I can answer some of your questions. But as you know, its the worst time to move anywhere without a job and place to live. California is about the most expensive place to live in the USA. There is a housing shortage and a lot of wealth here so housing is costly. Plus seems like most everyone is out of work during this pandemic. There is work in health care but you have to be licensed in California. There is probably work in grocery stores and big box stores. There is a need for elder caregiving, don't need to be certified. My son works in the wine country, north of San Francisco in a restaurant. Everyone in the hospitality/restaurants/wine is laid off due to the shut down. His unemployment is around $200. week plus some stimulus. Like you said, not enough to live on- he lives with me. My advice is if you come here, make sure your friends are REALLY committed to having you stay with them long term. Make sure they are very good friends because you wouldn't want to be without a place to live and no money. It would be better if you had a safety net like parents/family that could help you if you need it. So thats the bad news-
Check out Craigslist for housing and jobs. Search the area that you are looking to move to-
sfbay.craigslist.org/
Yes, you can get health insurance without a job in California. Everyone can get health insurance. California is very generous that way, but not all states have free health insurance for low income people. Depending on your income and assets, it would come under the programs- Medicaid, Medi-Cal, or Covered California (ObamaCare nickname). To get enrolled you have to go to a health clinic in your area and talk to a counselor there to enroll you.
www.dhcs.ca.gov/services/medi-cal/Pages/DoYouQualifyForMedi-Cal.aspx
Obama eliminated the "pre-existing condition" discrimination. You can get insured no matter what illness you have or have had.
Finding out if Promacta is paid for is a more complicated question. You would have to know what health program you qualify for then research if Promacta is on their list.
If you get too sick to work- well, that would not be a good scenario here. To get disability you have to have worked for about 3 years. Then you have to qualify, ITP does not qualify. To get unemployment, you have to have worked for 1-2 years. You have to pay into those programs. The harsh reality is that there are over 150,000 homeless people in California and they most all have illnesses, emotional problems, or years of poverty has rendered them unable to work. And they have few resources available except for health care. Here is a link to info about temporary assistance-
www.benefits.gov/benefit/1229
Take care and hope this helps in your decision. I am in my 60s so PLEASE take that into consideration, I have a different view of what is wise than a younger person. If you are young and resilient and willing to work hard and hustle, you can make it. I came to California in my 20s with no money but lots of energy (and parents I could fall back on). Good luck in finding your right place in this world!