I would really like to learn how to play ragtime on the guitar. As a teenager I took guitar lessons. I learned to sight-read and basic chords, but not much beyond that. Years later, I am learning again on my own and would really like to play music I enjoy. Where should I start in order to build towards playing ragtime?
This is a generalized answer but it should at least give you an idea of what’s ahead for you. Ragtime is played fingerstyle, like folk, country and bluegrass mostly is. In some ways it is more similar to classical guitar than to rock, pop, r&b, modern jazz and blues, styles mostly played with a pick. The reason for that is like classical guitar, the right thumb basically plays bass lines (for a RH player) and the right index, middle and ring fingers handle playing melody and chords independently of the bass line. It is like ragtime piano in that there are generally two things going on at once, a low part (piano LH, guitar thumb) and a high part (piano RH, guitar fingers).
On a more practical note your right thumb will be playing mostly quarter note bass lines, varying between the low strings to create patterns like 1,5,1,5, or 1,3,5,3. Your right fingers will be plucking melody and chord notes that sometimes fall on the bass notes and other times fall on the off beat 8th notes (usually with a swing feel) between them, thus forming two independent lines. This style uses mostly open and barred CAGED chords and their variations so make sure you’re familiar them and their minor and 7th varieties. A good place to start is to learn to play basic bass lines on common chord progressions and then start adding a chord on beat 1 or beats 2&4. It sounds like you want to learn on your own so I’m sure there are lots of good books and online tutorials and instruction on the style available. It is off topic to make specific recommendations but here are a couple of YouTube video examples that walk you through some basics:
It is not easy at first, even for an experienced guitarist if they are not familiar with the style or fingerstyle guitar in general but like with anything else it becomes easier as you work on it and develop the motor skills and muscle memory you need to play it.