Here's a tutorial on syncing in REAPER:
http://www.homebrewedmusic.com/2010/...deo-in-reaper/ There are other REAPER video videos on the site as well, the program has been enhanced for video quite a bit in the last year or so. Here's the latest post I did:
http://www.homebrewedmusic.com/2016/...eos-in-reaper/
I've used other programs that are free.
Shotcut:
https://www.shotcut.org/
HitFilm:
https://hitfilm.com/
Avidemux:
http://avidemux.sourceforge.net/
There are a number of commercial programs that support multiple tracks and syncing and cost under $100, you can see a bunch of choices here:
https://www.bhphotovideo.com/c/searc...52f3160ebd3c37
Any and all of these options may be stress-inducing depending on how much patience you have for delving into computer obscurity.
Fran