Dude, priorities. You might want to gather enough food to survive the first night in before trying to build a society from the ground up. You could even do it right after gathering said food & water, ex. choosing leaders to fairly divide up the rations & keep the masses in order.
That, and it'll fall to you to remind those who had forgotten why they're here in the first place. Which is in turn achieved by reclaiming your own memories, or getting someone who did that first to do it for you.
Lastly I should remind y'all that making speeches isn't the only way to round up supporters. Feed 'em, give them water & shelter them, prove that you can be a leader in more than words, and they'll join you at your speeches in ever greater numbers even if they don't remember anything else & even if you don't really outline what you can do for them beyond 'I've taken care of you in the past and will continue to do so in the future so join me, m'kay?'