The 20 year-old told US Billboard magazine: 'I already have drawings in my journal of what the stage should look like. I know a few of the setlist order - I want there to be an entire wedding scene on the stage.'
The Mine singer also opened up about her track Innocent - her song about the Kanye West incident.
She said: 'That was a huge, intense thing in my life that resonated for a long time.
'It was brought up to me in grocery stores and everywhere I went. And in a lot of times in my life, when I don't know how I feel about something, I just say nothing. That's what I did until I could come to the conclusion that I came to in order to write Innocent.
'Even then, I didn't talk about it, and I still don't really talk about it - I thought it was very important for me to sing about it.'