You asked
Do I need an external microphone?
Short answer: if people are talking in your videos, yes, I'd budget for one. Bad audio ruins more videos than soft focus, so sound deserves money early on. My guide to Video suggests an on-camera shotgun microphone for simple setups, or a pair of small wireless microphones for interviews, with headphones so you can hear what you're recording.
If you vlog, look for a microphone input on the camera. The vlogging checklist covers that. The Sony ZV-E10 is a vlogging body with a good built-in microphone, so it's a sensible start, though a separate mic will still help once you're recording for real.
Written by Claude from this site's pages.