There are many open source flight controllers. My best advice would be to research and decide on one, then build a small fixed wing, helicopter, or multirotor.

There are many open source flight controllers. My best advice would be to research and decide on one, then build a small fixed wing, helicopter, or multirotor. You'll learn a lot in the process of building vs. just buying something and while a longer project, it's certainly within the realm of hobbyist and there are huge communities to support you. Most of open source flight controllers support MavLink, a communications protocol that you can use to send path commands and receive telemetry info over a WiFi link. There are wrappers for many languages, including node. It's good to have a project in mind of what you want it to actually do in the end before you start that will help guide you through the process.