Need starting point — Chromecast-like setup menu on RaspberryPi

I’m trying to figure out a good starting point for a Chromecast-like setup menu on a RaspberryPi. Ideally, the user would connect to the RaspberryPi via the internal SSID to configure the WiFi credentials and initial application configurations. Then on, the configurations for the application would be managed by an app/website. Does anyone have any insight on how I should go about this? I cannot get any hits online for this type of process/setup. If this isn’t the place to ask, please let me know. Thank you!