G'day & welcome to GT.[br][br] I've used both GT & JG in concert with one another. After researching and trying most including JG, I went with GT. I've been here for 3½ yeas now. [br][br]Justin has only quite recently reorganised his website into structured modules as such, i.e. Beginners Grade 1. They're mostly his older You Tube lessons now better structured collated into stages than the motley assortment as was. JG is OK. His material is good, importantly, now improving as a structured syllabus. Everyone has a preferred learning style, but if you had to choose just one, GT is the still the pick in 2021 IMV.

I use several. i.e. I did buy, use and complete JG's subscription model Music Theory for Guitar course a couple of years ago and found it very useful.

Re GT. Check out the syllabus and see where you are up to equivalent to JG Grade 1 and get stuck in from there. Stick with the chords as you've been taught at JG, i.e. open A, if you find adaptation a challenge. Later you'll use several forms and fingerings of the same (open) chords anyway. GL & have fun.