It doesn’t matter where you start. Just start.
Here are a couple of recordings from my new home on the upper Thame. https://soundcloud.com/user-143636955/owl-trill-and-blackbirdhttps://soundcloud.com/user-143636955/reedwarblerRecorded on a old Zoom H4. Fun to run these through the free SpectrumView app.
Testing the DIY Hydrophone, recording some molluscs in a rockpool, munching away!https://www.youtube.com/watch?v=0ThrlvRBt4Q