Welcome to California.
First, Go to your Local Tractor supply or equivalent and pick you up on of those slow moving vehicle triangles. And mount it on the back of your tractor where is will be very viewable.
Go to the State DMV dot gov and in the vehicle codes look up “Implements of Husbandry” and read all sections and print the ones off that pertain to you and stick them in your back pocket.
Then check with your city and see if they have there own restrictions or if they follow the state guidelines and if they use the state guidelines, then Jump on tractor fire it up, make sure the yellows are flashing, turn the head lights on and go for it, and always pull over for faster vehicles. “Trust me that if you show respect to other drivers the CHP will be your best friend and they will make there quota and repair the state budget problems writing tickets to those that pass you illegally”
Last, with your printed and read documentation, if a cop gives you a hard time, Just sign and meet him in court.
I live in the central valley and we are overwhelmed with idiots, before I take off from the farm to the house or to a repair shop, I notify the city and the CHP of the planned time and route and I love it when they follow me, Hell sometimes I get a free escort thru town from the traffic division who can turn out 6 to 8 tickets on my route.