I learned on a Gentle Lady which I also built. Find a big field, don't underestimate how big it needs to be. Gliders are the hardest planes to do a precise spot landing with because they just keep gliding and gliding and gliding. You think it's time to flare for a landing and it zooms 15 feet into the air instead then you dive back to a low altitude and it regains the speed it previously had that's too hot for landing.
The key to a good high start launch is to throw the plane level, not up. The first 10 ft or so of the launch accelerates the plane to flying speed and then it will rotate to the up direction automatically. All you need to do is keep the wings level with the rudder. A sharp dip at the top will help release the bungee cord.
As my skills grew, an experienced glider guider friend of mine would launch and land the plane for me at the dam on Lake Travis. With a southeast wind, you could fly on the lift there until you were tired of it or the reciever batteries were dead. Huge flocks of buzzards would show you where the lift was. It was an easy place to fly but it had a tiny landing zone.

One of the advantages of starting out with gliders is that you won't freak out when your powered plane's engine dies in mid air. You are now flying a glider and you already have the skills needed to deal with it.