Start by being a curious cat and observing the world around you - like, have you ever noticed how stuff happens? Maybe you've seen a weird bug or a funky plant, and you're like, "Hmm, what's up with that?" That's your observation! Write it down, take a pic, or draw a doodle - just remember it.
For example, let's say you notice that your algae-filled aquarium is growing like crazy. You're curious, so you jot down some notes and start thinking about what might be causing it. This is where the magic begins!