I like the aesthetic of sm, eldar, drakhari, tau, orks. Gameplay wise I don’t know what I will prefer as I’ve never played a full game or my own list.
So how the hell did you choose your first army?
That is a very good point. But enjoying the painting side will lead to needing to find a second army much sooner. Find that right balance of fun to paint, right general tactics (horde/shooty/etc), and enjoyable lore. It doesn’t need to be the max on all three, but if you really dislike one of those aspects you’ll be very disappointed.