Update info? Unrelated sorry I just realized I need to update my profile pic ( which I just did) and…

Update info?

Unrelated sorry I just realized I need to update my profile pic ( which I just did) and my username but it won’t let me edit it even in the edit settings... does anyone know how to change it? I’ve seen a few people change theirs over time and Also I can’t find where I can email admin to answer for me ? Thank you so much ladies!