I would recommend making a dive on Scuba before Abalone diving. Many divers new to California's North coast have trouble spotting them the first time they dive. Scuba will give you time to observe them and the environment at a comfortable pace. Carry a caliper with you so you can get used to what a legal 7... Abalone looks like. Once you train your brain, they stick out like a sore thumb. It is also a good opportunity to observe the animal's behavior... being a snail, they move pretty slowly so it is hard for new freedivers to do on one breath.
Observe how they attach to the rock when relaxed and suck down harder once spooked. Also remember that Abalones are basically hemophiliacs. A small nick will slowly kill them so understanding how to get them pried off the rocks without damaging them is important in case you misjudge their size and have to put one back.
The North coast is similar to Monterey, but different enough to take the time to orient. It is typically a little colder, has lower vis, thicker kelp, and more surge.
I would also suggest taking some time to dial-in your gear for freediving. You need to be buoyant at the surface, but neutral at your target depth or 33', whichever is shallower. You waste way too much air fighting buoyancy. You may be in 8' of water at times. Dive with someone, don't push yourself too much, and brush up on shallow water blackout and Samba. Spit your snorkel out of your mouth as soon as you start the dive. It is prudent to alternate dives with your buddy since your rest time on the surface will be longer than bottom time.
You also need to dive warm. You quickly learn to "relax to the max" before making a freedive, bordering on Yoga. Your wetsuit will provide max insulation because it will spend very little time compressed, but you will be more acrobatic so water circulation is worse than on Scuba. Mostly, relaxed states don't generate much body heat.
One of the best pointers I know is to use a float line attached to your Abalone iron. The idea is you drop the iron at the end of the dive/breath. After recovering you swim back down the float line and continue. It is basically 30-50' of colored plastic tubing plugged at both ends so it floats. Polypro rope is not nearly as good because it will not pull through kelp as well. It will not only mark honey holes, it will keep you from swimming the same territory over and over -- think low vis and surge.
There are two rules at play: You will always see the best abs at the end of your bottom time, and they look bigger in direct proportion to blood CO2 levels! This will give you time, especially in a surge. Rules, and especially new divers must use a caliper before removing an Abalone from the rock. It can take several dives before deciding which one to take.
Don't forget to get your fishing license and Abalone card/tags. Take time to study the rules and understand the intent behind them. Becoming a proficient freediver is a lot like learning to ride a bicycle. Lots of skinned knees, but great once you get over the hump. I have come to enjoy freediving just as much as Scuba, and it will make any Scuba diver much better. Have fun and eat well.
