Starting together

Hi everyone, my gf and I wanna try WoW as ESO feels empty and we enjoy to play together. We know close to nothing about the game. I love the green glowing stuff and am looking at the Deathknight and she will pick something that throws flowers and heals everyone, I think it will be a druid.

Are there any restrictions like horde and alliance are seperated we need to be aware of to not end on 2 different edges of the world?

Thank you in advance