Filmic is already installed and set to the default view transform in 2.8. This video is a good overview to learn about it, but there's no longer any need to install anything. You can find the settings under Render/Color Management.
Your display device should almost always be sRGB. View transform should be Filmic.
You can change the Look to adjust the contrast. You can also adjust the exposure or gamma as desired for your render. Or you can select the Use Curves option and then you can work with a standard RGB curve tool like any video editor would. Another alternative is doing this stuff in the compositor, where you would still work with lift/gamma/gain and curves as nodes.
