Food forest in an existing forest

I'm enjoying this video by David the Good.  I'm trying to establish a food forest in an existing woodland, and I think David has some great advice about coppicing existing trees, retaining their usefulness while keeping them from shading everything else out:

https://www.youtube.com/watch?v=BS7kAdKM0Fw

In spite of the challenges, I am very grateful that I ended up with a field. It's a blank slate and I don't have to grapple with some of these issues, or with choosing what to cut down and what to leave. But there are pros and cons to every site I suppose