How do you sign out of iCloud without deleting data from the device?

I've read a few of the submissions with similar questions, but I can't really find the answer I'm looking for.

I have two devices - "new" and "old", let's call them - I've synced my data from 'old' to 'new' using the iCloud backup, so all of my data is now on 'new', but still also on 'old', yet I want to sign out of iCloud on 'old' so that someone else can use 'old', without it interfering with my data on 'new'. When I go to settings on 'old' to sign out, it says "Delete Account" and "Deleting your account will delete all its data from your iPad". (As I've seen some posts say that the data is fine, I find this pop-up quite misleading.) So I want to clarify what this actually does And make sure that:

1) The iCloud account will stay (even though it says delete account), so

2) The data on 'new', which had been backed-up from iCloud, remains on 'new' (and in the iCloud)

(I'm sorry if I'm not clear enough or anything, so feel free to ask, as this is my first post)