Audio is actually pretty simple when you think about it. Sound bounces off flat surfaces, and if you’re recording in a room where sound is bouncing around, it’s going to sound echoey, and bad.
But luckily, sound is absorbed by soft surfaces, reducing the amount of bounce in a room. That’s why we have these panels on the ceiling, and have these large curtains, to stop sound from bouncing as much off these walls.
On top of this, the closer your microphone is to your mouth, the better audio you should have, because the sound is going directly into your microphone, rather than bouncing around the room, and then going into your microphone.
There’s a lot of different microphone options available, but I like to have a decent on board mic, like this Rode Video Mic Pro+, plugged directly into my camera, this is like my standard go to setup for my YouTube videos (90% of the time this is what I’m doing for capturing my audio). And then sometimes, if I want to capture a wider shot, I’d either shout louder and accept some room echo, if that’s the energy of the shot I’m going for. Or alternatively, I’d use an extension cable, so I can still shoot a wider shot, and have the mic close to me. If I didn’t want the cable getting in the way, the other thing I could do, is hold or clip on to your top, a wireless mic.
Another option would be something like this podcast mic. This option offers the best, rich sound, but it means you have to have the mic in shot. Good for this sort of educational setup, but for the sort of videos I like to make where I’m changing angles a lot, and moving around so much, I prefer the flexibility an onboard mic offers.
Each of these mic options have different styles on camera, and balancing what kind of content you’re making vs the setup vs the audio quality is something important to consider when you’re filming.