There's a fundamental law of audio: The camera position is never the best place for the microphone, but it is sometimes about the worst.

If you're going to be talking over the video, you probably want a lavalier mic that will clip on to your shirt collar with a small recorder in your pocket or clipped to your belt. It will let you move around without altering the sound quality. If the mic is mounted on a stationary camera and you move around it will sound bad in stereo and even if you drop to mono, the sound strength will vary all over the place. One of the Zoom recorders or a 2nd hand Sony PCM should be enough.

A Canon Vixia or something similar will be a good camera for what you're doing. I have 5 of them that I used for spot video when recording classical orchestras - sometimes had as many as 8 to 10 cameras running at a time. I never paid more than $100 - $125 for a refurbed Vixia at B&H. I'd avoid the GoPro - the lens is too wide for most stuff and the camera itself is too fussy - I have 3 of them that I'd use for things like a very wide audience shot from the back of the orchestra to pick up applause etc. I could trigger them from a smartphone app but the batteries don't last very long and the cameras were prone to losing the connection to the phone. Your smartphone should give adequate video but the audio on these things is at least three steps worse than atrocious.

My main cameras were a JVC shoulder mount, a 2.5k Black Magic, a couple of Black Magic Pocket cams, and a Canon C-100. these are all nice cameras but gross overkill for what I think you want to do.

I've used Vegas as well as Adobe Premiere Pro - I recommend Vegas since it has very good audio capability. It actually started out as an audio package and morphed into a video application. It's one of the most user friendly of the bunch and not too expensive. But it's PC only. I already have the full Adobe suite so no reason not to use Premiere but it has a steep learning curve. Black Magic makes a version of their DaVinci Resolve application available free of charge. It started as a color correction tool that was used by most of the Hollywood studios, but in the last few releases they've added enough general editing capabilities to satisfy most editing requirements. It's a fully professional (ie steep learning curve) piece of software even in the free version By the way, did I mention that it's free for download from the Black Magic website?

https://www.blackmagicdesign.com/pro...avinciresolve/

A couple of good online forums

DVINFO.NET - Mostly aimed at digital video but has a rather good Audio sub-forum.

Gearslutz.com. Strange name but most of the members are professional sound guys.

There's an application called Plural Eyes. If you record into the camera you can use that as a synchronization track and it will sync up a bunch of audio tracks from separate recorders. after which you delete the camera audio track. Works well, but it's probably overkill and it isn't free.