Hi Denis
Lisa's fundamentals are really fundamental. Great for someone like me who really had no skill set to begin with, but I would suggest that if you already know some basic chords and have some skill at chord transition as well as some basic theory, then maybe focusing on something else may be better for you.
I like Chris' suggestion of songs, or maybe you want to focus on a style like blues or something. But I am not sure what is open to you for the 6 free lessons. The songs are broken up into multiple lessons, so you may go through your 6 free lessons and not complete the song. Same applies to other courses, it sounds like the 6 free lessons are just to give you a taste of the competency of the site and instructors.
I think for someone to give you the best advice, and it will probably come from Christopher, it would really help if you laid out what you do have under your belt.
For instance, how may chords do you know and what are they, do you know the chords for each key? Do you know the associated major and minor scales etc etc. The more information you provide about your current level the better.
Good luck.
This year the diet is definitely gonna stick!