Long necks are so called because that is what they look like, they have the scale length of the next size of uke, usually, (but I also have a soprano bodied, tenor scaled uke, commonly known as a giraffe neck). They have a certain appeal to me, because they are different, but they are nice to own.
I mainly pick tunes, so the extra frets make a difference.
As a beginner, I always suggest starting out with a concert scaled uke, this will let you decide how you feel about ukes, I feel, as it's an in between size, with good sound quality, & space for your fingers, which will also let you try out low G, as you have more resonance than a soprano, & longer string length, which helps improve sustain.