If you want to boost your WiFi signal from the park I would recommend the Alpha WiFi antenna. I have used one of these for years and it is not as powerful as the new ones. But it does a great job and easy to use.
Link
If you want to boost your cell phone signal I would recommend the Wilson Sleek. The Sleek does a great job and simple to use. I would get the Home kit with it also so you can use it at home as well as the 12volt option it comes with. The Sleek also works with Jetpacks also.
Both of these options above require very little to set up. Check out Amazon.com for each of these.
Joe