My first guitar was a nylon-string (classical type) guitar; the theory was that the strings would be a little easier on the fingertips for a beginner than steel. That may have been true, but it was still necessary to "experience a little discomfort" while developing calluses -- perhaps I might as well have gone with a steel-string model from the git-go. When I did switch over, I had to adapt to a narrower fingerboard as well as "sharper" (harder and thinnner) strings.

Any instrument is difficult at first, before it becomes relatively easy to produce some *simple* music. It never stops being difficult to keep improving -- there's always something you still can't quite do.

My advice would be to select an instrument, and then songs and pieces, that you *really* like. Persistent repetition is the only way you'll get anywhere, and the only way you'll be able to do it (i.e., the only way you'll *want* to -- enough) is if you're trying to do something you love.