Something to add on:
Talk and focus on the future. Look at our teams
handbook. Use content from there to make up your lecture. Get your team organized, and give them some responsibility so they feel important. You can also go into how the regionals and nationals are so exciting and stuff. Your goal is to spark their intrest, get organized, and start building a bot. Sadly though, unless this is done real well, you will be putting in a majority of the work. You also want to get your mentors intrest, and maybe your enthusiasm will help. See if you can recruit some other teachers into the team. There is a lot going on, too little time, prioritize and do it right, we are here to help.
I do hope getting them all together is not such a big problem.