on your profile
ok so first click this your username on the top right
Ohhhhhhhhhhhh I seeeeeeeeeeeeee thank youuu
yw
😀
it should bring you to something like this. This is My homepage
your is probably just a white screen next your going to want to click this its on the top LEFT it should bring you here
then click this and change your profile to whatever you want
your username on the top right 
its on the top LEFT it should bring you here 
and change your profile to whatever you want