If this is your first plane I would not advise a hand launch.

Even with experience you want the first flight to be off a hard surface to give you the opportunity to trim out the plane.

You need to do this before you attempt a hand launch lest you end up with a very fast air to ground missle.

The wheels are too small for anything but very short ( think putting green ) grass, packed dirt, or asphalt.

They will catch in grass and the plane will nose in hard at landing.

A skilled and experienced flyer could perform a "stall" landing with a bit of headwind, to plunk it down on the grass.

If you must land on grass, you might want to consider removing the wheels ( after your first flights ), and placing strong ( with thead mesh ) packing tape along the belly. Also skid guards would help protect the wings. Some people also tape the leading edges of planes that will be landing in the grass w/o gear.