I have researched this topic somewhat, and I have yet to find a state law concerning lasers.
Obviously federal laws still apply. You are not supposed to import high powered lasers or sell them in the US according the CSPS (a federal agency, therefore their regulations only apply in cross-state transactions), though many still do this as the enforcement is lacking.
There are no federal laws that apply to a hobbyist building his on lasers (correct me if im wrong), because you are not entering into "commerce".
It must be said that pointing any laser at a vehicle or plane is a federal and likely state felony.
All that being said, I HIGHLY suggest buying a laser from the forums here, if not here then in one of the jetlasers group buys or from lazerer.com.
For a first laser I would suggest green (532nm, somewhere between 100-300mW) as it is the brightest color that can be cheaply obtained with a relatively low amount of danger. Notice the word relatively, a laser like the one I describe will still instantly blind anyone caught in the beam/reflection (you would be surprised on the amount of things lasers can reflect off of). Therefore, you must buy appropriate laser safety goggles and only operate your laser without them when you are outside and pointing in the sky (away from any reflections, and do not point it at anything within a reasonable distance, its bad for your peepers).
Also, it would be a good idea to read up on the properties of Green lasers, as there is alot of misleading that can be done with a website that sells green lasers in particular.
TBH when I use my lasers outside I sit and look at the stars for a good 3-5 minutes, all the while looking for planes in the sky.
Your laser would almost certainly not even be noticed by a commercial jetliner at a reasonable high, but I live near a small airport, so I can never be too careful.
Please take my advice with a grain of salt; the best way to learn is conduct ones own research. LPF is the best source for this information IMO
Whereasbouts are you in Cali if you don't mind me asking? No need to be specific, ill probably know the region you are talking about.