Classical guitar from scratch to grade 8?Watch
It honestly takes years, and don't forget Music theory (Grade 5 Min.)
There are other factors, but a main one is talent. I suggest taking it up anyway, and seeing how you get along.
good luck In your decisions
I'd give it 2-3 years if i'm honest.
Took me 3 years to master guitar, but then I had already been playing piano since I was 7 or so and am pitch perfect. Most people I know it took them 5+ years.
1014, were you also taking lessons with a tutor during those 10 months or did you just go through the books yourself? Also, did you go through each grade one by one or did you skip any? And hows your guitar journey going now?