Best bet is to record at the same time but with different sources. This is my setup:
* Standard XLR condensor mic for voice audio into mixer
* GUITAR > BOSS-001>STEREO INPUT ON MIXER
* MIXER > USB AUDIO INTERFACE > COMPUTER
* CAMERA > COMPUTER
Then I use OBS (https://obsproject.com/) to make the recording. It puts audio and video together. OBS saves it as an .mp4
Costs (I am a cheap person. Much better equipment out there but this works for my home hobby):
* Mic - Behringer Condensor mic - $20 (sweetwater)
* Mixer - Behringer 12 port - $50 (sweetwater)
* USB Audio Interface - Lexicon Alpha - $50 (sweetwater)
* OBS - free software
* Computer - Can be anything.
This way you have zero syncing needed.