Which state is best for filing a divorce proceeding?

In order to properly answer your question, you need to state where your spouse is living, how long they have lived there, whether they are living there temporarily or permanently, where you both last lived together as husband and wife, and for how long. Also, divorce laws vary by state and there can be significant differences on property distribution issues, child-related issues, and other issues, and wherever you file, the court of that state must have jurisdiction over the issue(s) being decided and both parties.

Florida, it appears, would be the place to file, but that would depend upon having been a resident here for 6 months, and it would also depend upon which state would have the best laws for you to file in. I can tell you about Florida law, but not about California law.

I have no idea what difference there would be because I only deal with CA law. You probably have to file in FL because that is where the child lives and custody would normally be decided in the child's home state.

California tends to have the highest child support calculator and is a community property state. However, you should consult with an attorney in each state to determine what works best for your individual situation. "Temporarily" sounds like you do not reside in Florida, so should really file in California. However, there are other considerations, including where the other side lives and whether the other side will mediate or litigate. Obviously litigating in a different state to the one you live in is not the ideal situation.

Federal Law says the case should be brought in the "Home State" of the child. Her home state would be Florida if the child has been here over 180 days.