Nice choice of avatar.
Started because of all the memes. Stayed for the awesome story. Currently reading JJL and I started with the manga.
It's hard to pick an overall fave character, but I'd have to go with either Diavolo or Doppio. All the mysteries make it super interesting. I do adore Gyro too though.
Johnny is my fave JoJo, with Gyro being my fave JoBro. Valentine is my 2nd fave JoFoe after Diavolo.
As for a fave Stand... Again, a very hard choice. I separate the sentient Stands from the non-sentient ones when picking faves.
So fave normal Stands would be: Diver Down, White Album, D4C, Tusk and, Soft & Wet. Fave sentient Stands are Sex Pistols, Foo Fighters, Whitesnake, Paisley Park and, Spice Girl. Honourable mentions for Weather Report/Heavy Weather and, Echoes ACT 3.
Steel Ball Run or Vento Aureo would be my fave part. I really did love Stone Ocean too though.
Lastly, I haven't created any OCs for the series.