I'd like to do a youtube video series where I talk about various subjects in front of a camp fire (with all the sparking fire sounds, crickets etc) out in nature. For practical reasons, I can't be out in the woods physically doing this every time I have something new to talk about.
Which is the best non-subscription program for PCs where I can simulate this atmosphere (and put me in the middle of it) and it seeming as real as possible?
Will you be recording yourself in front of a green or blue screen and keying out the background? If yes, you should be able to do this with any basic editing software. There is a free version of DaVinci Resolve (version 12.5). Go to the site and scroll to the bottom for the download links. It may take a little while to learn but should be worth the effort. If that is too much, effort wise that is, then you could try one of offerings from Sony (Vegas Studio), Adobe (Premiere Elements), or Corel (Video Studio), or any of the many non-subscription software choices.
That all depends on how in depth you wan to get with motion graphics and the other things you can do with an After Effects type program. If you can find a similar program at a reasonable price then it might be worth taking the time to learn it.