I've seen and heard multiple co-founder friendships fall apart once things started to get "real". Good luck!
This effectively encourages you to not form a company in CA if it's only expected to produce a tiny amount of income.
Take the time to read about this before doing anything. One impulsive action could lead to thousands of dollars in annual fees and even more in filing costs (accountants, lawyers).
In your case of a 50/50 split, make sure your agreements also have a clause that deals with disagreements. IT's likely you'll come to a point in your business where you do not agree and 50/50 ownership can make your business stall. Codify how those disagreements are solved before you get there.