The essentials — the rest we decide when we speak.
HAS A BUDGET BEEN SET?
FORMAT
YOUR ORGANISATION
YOUR NAME
WHERE IS IT BEING HELD?
THE EVENT, AND THE DATE — OR THE WINDOW, IF IT ISN'T FIXED
AND WHO ARE THEY?
HOW MANY WILL BE IN THE ROOM?
I read these myself, so it may take a day or two — but it will be me who answers, not a template.