One of the first things you will need to download in order to stream with customization (alerts, camera, custom layout, etc) is a broadcasting software. This is the main program that will bring together all of your elements and broadcast them directly to your platform of choice or record the video locally. There are quite a few options in addition to the ones in this article, but these are some of the currently most used. Below are the two top broadcasting softwares with guides from twitch.tv on setup.
OBS Studio – Open Broadcasting Software
OBS is a popular broadcasting software and can run on Windows, Mac & Linux. It’s free, open source and constantly being updated. It’s very easy to learn and if there is a need or want for a plugin, there’s a chance (with enough community support) it will be developed.
Xsplit can do many of the same things OBS can do but has some different features, such as an on screen drawing tool and email support. Xsplit is available for Windows only and has both free and paid premium plans, but a paid license is required to use it for any commercial purposes. Below is a chart comparing the plans.