You can go back in time, but all you can do is see the world and talk to people. What would you do?

Someone has invented a way to send you back in time, but it’s only a projection of you. This projection will allow you to see the world around you, talk to people, and hear what they say in response, but that’s it.

You cannot smell, taste, or touch anything in the past. You cannot pick up a gun to assassinate Hitler or eat the last dodo bird (though you could try to convince someone else to kill Hitler or describe to you what fried dodo tastes like).

So with those limitations, what would you do first? If you could take more than one trip into the past, what else would you want to do?