Thanks to William for a great reply as usual.

Tom, what you are describing is a typical learning experience.  You are doing fine.  Keep practicing some every day.  Don't worry about getting it perfect.  Keep moving forward to learn new ideas & skills.  Make time to keep reviewing old material to gradually improve.

Learning guitar is a constant process of gradual refinement.

The good thing about the fundamentals courses is that there are training song structures.  But you should definitely add in learning some songs that you know and enjoy to keep you motivated.  After all that's why we learn all the skills & ideas: to apply them to playing songs we love.

The landing page of the Fundamentals courses have songs linked in between the chapters.

https://www.guitartricks.com/course/fundamentals2

And the made easy songs collection is a great place to look for songs at beginner skill level.

https://www.guitartricks.com/songs/beginner

Hope that helps!