Simple Tips for speaking to a large audience -

First - consider that you are actually speaking to individuals rather than a group.

Second - don't think "project" which is just general loud. Think - "direct" (your voice) which is more intentional.

Now, direct your voice to individuals in the room/space/auditorium even if you can't see them (on zoom - tape a picture of a friendly face just under your camera lens - speak to him/her) - talk TO them.

Imagine you are having a one to one conversation with these individuals - in the back of the room, front, middle - adding enough energy to be heard by all. Keep breathing.

Lean in physically (weight just a little bit forward - front footed as opposed to back footed) and energetically - excited to engage.

Let me know how it goes :)