。
Shall I show you around this town?
Literal
I [subject-が] this town [object-を] guide do-[shall-ましょうか].
しましょうか is the polite volitional (する + ましょう + か) meaning 'shall I do [X]?' — a polite offer. 案内する ('to guide, to show around, to give directions') is the standard 'tour guide' verb. A classic polite offer from a local to a visitor.