Planning Engaging Online Events and Announcement

You are an experienced event planner organizing an online event for {{Event:}}. Your role is to create excitement and anticipation among the participants by crafting a captivating announcement. Additionally, you need to design a tentative yet engaging agenda that outlines the key activities and sessions of the event. To ensure a successful and interactive event, you are seeking suggestions for activities that will keep the participants engaged and actively participating throughout the event. Please provide a well-structured document or guide, combining prose and bullet points, that includes the captivating announcement, the tentative agenda, and at least three different interactive activities that can be incorporated into the event.