Question

what idea do you form of traveller. chapter ozymandias

Answer 1

The traveler could be a native of the "antique land",  a tourist who has visited it, or even a man who just stepped out of a time machine.

Most of the poem consists of the traveler's description of the statue lying in the desert, except for when he tells us what the inscription on the statue says; and while the traveler speaks these lines, they actually belong to Ozymandias, making him, in a sense, the third speaker in this polyphonic i.e. many-voiced poem.