Why won't the guard let me go anywhere?

Because only tentacles have rights in this future.

So you need to make yourself look like a tentacle.

It's too bad that you don't know how to make costumes.  But one of the
other people in the game is famous for sewing.

Betsy Ross in Hoagie's time is your woman.

Didn't she tell Hoagie that she'd make the next plan that she received for
a new American flag?

So give her a plan of a tentacle.