I've seen excellent drivers wreck great cars from a simple mistake that would have never caught them otherwise. It can happen to you too. This is the most fun you can have with your clothes on, but it is serious stuff too. Treat it that way. Stay in your lane at all costs.
Most tracks have plenty of run out area.
However, other tracks like North Texas Dragway, as soon as you pass the finish line, you need to get on the brakes. When running the quarter mile, you will be running close to 100 mph at the finish line. If you slam on the brakes at those speeds, it is VERY easy to upset the chassis of the car and loose control, so be careful to not brake too hard. Before you run, know where the turn off roads are located. Speedworld has 2 turn offs, with one of them located at the very end of the run out area.