The 420 is commonly used as a high school and college level trainer. They sail well in a reasonably wide range of wind speeds. They can be single-handed in moderate conditions but can be a real handful single-handing in a breeze. They may be a little limiting if you intend to tow it to the lake and
rig it each time since
rig set and drop can add an hour or more each side of getting underway. In a light air venue like lake sailing, where the wind can disappear entirely they are also limited by their inability to carry an outboard or oars to get you back home.
Jeff