Difference between Sunfish and Laser (as well as shameless plug for the Lido 14)
The Laser is going to be much wetter, more weight sensitive (ie capsize easier), but way faster than a Sunfish. As far as learning goes, the Sunfish is likely a better boat.
Don't forget the Lido14, it is a beamier & drier boat than either the Sunfish or Laser. There are thousands of them which also can be picked up for nil. Still one of most active Dinghy Associations in USA.