I’d check out that tutorial I posted, once you feel comfortable with the basics of JS you may also want to take a look at https://tonejs.github.io/, which provides a layer on top of WebAudio with useful functionality like synths, sequencers etc. Can save a lot of time!
There are many other great tutorials and open source WebAudio projects out there too. Have fun, hopefully you can post something you have made on here in the not too distant future! Like I say, feel free to give me a shout on email/twitter if you need more advice.