You don't need to ask, you can show up at any time, anywhere and protest all you want. A lot of people do that all the time. You just don't have police protection unless you request it it advance.

This is because of limited police resources, not because they can chose what speech to approve or not. It also works both ways, if they where trying to limit your speech they wouldn't have enough resources to arrest you anyway.

You don't need to ask, you can show up at any time, anywhere and protest all you want. A lot of people do that all the time. You just don't have police protection unless you request it it advance.