Is there any repository of lidar data for US? Especially coastal states like Florida, Texas and California?
USGS's 3DEEP data for the National Map covers lots of federal and private land. Open Topography holds lots of research data funded by various federal organizations (NSF, NOAA, others) amongst other stuff. State-level Departments of Natural Resources very commonly host survey data.
A lot of the country isn't covered, and what is there is pretty dated, but there's a recent capture of the entire west coast available.