If you know how to fly off land, you can go out and fly off water and have fun the first day. This is especially true if your floats are selected properly for the plane and rigged right.

Techniques are not much different, and the plane does not fly much differently with floats. The transmitter sticks all work in the same direction. The big difference is that the plane does not sit still on the water, and any wind will blow it around. Forget crosswind takeoffs and landings...lakes are usually wide enough so you don't need to do that and a crosswind landing is ASKING to trip on a float, catch a wingtip, and make a big splash. Crosswind taxiing is a challenge, too. Hold the upwind wing down with aileron. Until you get comfortable with taxiing on the water, it's probably best to taxi as little as possible. Put it in the water, aim into the wind, goose it and take off. If you can plan your landings so the plane ends up directly upwind of your position, it will drift back to you if the engine quits.

Make sure there is a boat available to you.....You just can't walk out and pick up your plane if it goes down in an unplanned location.