You're going to need a chart, there's a few areas to look out for. When you get to the island, if there are already a lot of boats there, but there's a big area that's completely open, there's usually a reason. Like it's a foot deep. You also want to avoid Sand Island which is under water now, but not by much. It's out in the lake near middle channel. If that doesn't mean much to you, you need a chart. Really Jobbienooner isn't the ideal time to head out on the lake for the first time as it's a rafting and anchoring zoo.
As for launches, Metro Beach is probably the closest but is a long no-wake ride to the lake. Harley Ensign is a little farther north, but if you beeline it Gull, you can easily have a bad encounter with Sand Is. You would probably burn the same amount of fuel from either launch, but my advice would be to top off the tank and don't worry about fuel consumption. Instead worry about if you have an adequate sized anchor or two, docklines, and fenders.
Good luck and welcome to the site.