I live in San Diego County, And if you want to know when how and where to catch bimacs, im an expert in my area. Some people down at the beach are so fascinated they say I should start tours...anyway, You want to go out on as low a tide as possible, you probably since your a new timer will want to go only if its -0.3 or lower, although i have found them at tides as high as +0.87.
Once you have your date, you want to make sure you have a location. They like actual reefs, no just tidepools with sand and rock, they like rocks covered in seaweed and such. If you look at the pics I showed, you can see that there is lots of kelp and shells around it, living organisms everywhere.
Ok, now that you have your place and your time, head out to your spot. People ask me every time im out on the reef, "how do you do it?" because they look all day and can't find one. The reason is is that you have to get pretty down and dirty to find them if you know what i mean. You may be uninterested now but all i mean is above there gentle glares into the tidepools (believe me thats all they do and they expect to see everything on the tidepool sign when walking in). What you want to do is look for good rocks that are covered and well adapted into the reef (that means covered in small crabs, shrimp, kelp, and so forth), The ultimate rocks are the rocks that form small caverns in the tidepools, but I have found them under flat ones so dont be to picky and just flip rocks like crazy but be very careful when putting them back because you dont want to disturb anything else under the rock. While your flipping rocks, you will probably encounter many other small animals that after so many times at the tidepools dont thrill me anymore but they might for you.heres a list...
various species of small shrimp
baby lobsters
brittle stars
bat stars
tidepools schulphins-small fish that look like mudskippers, VERY common amongst the tidepools
sea hares (sea slugs)- gauranteed you'll find one of these
wavy top shells /w hermits in them (sometimes)
rock crabs
red crabs
ochre stars
giant sea stars
thats all i can think of but there more. its a blast flipping those rocks, but make sure you bring reef shoes and just in case wear swim trucks because sometimes a wave may nick ya when you dont notice. I bring a small net that can get into small nooks and cranny but primarily I use my hands for the octo's because they are deadly fast and are easy to lose sight of, so don't go thinking its an easy task! Have fun!!!
~Mike