Guitar uses the staff, and not knowing the staff does not affect your guitar learning.

I suggest you study in a musical instrument store first, so you can avoid taking many detours. If you learn folk guitar, you can leave the musical instrument store after getting started. I recommend you to buy a guitar self-study March pass, which was written by Liu Chuan. Then learn it yourself, because the folk guitar is relatively simple, and the teachers in the piano shop are generally not very good. After learning folk songs, you can turn to rock.

If you study classics, Brouze or something, you must find a good teacher. But it hasn't come down in recent years.

The price of each musical instrument store is different. Once I learned guitar in a musical instrument store, and it was 50 lessons. There shouldn't be much change now.