What do you call a person who is new in town? [closed]

I think what you're looking for is Newcomer.

(noun) 1. a person or thing that has recently arrived; new arrival:

She is a newcomer to our city.
The firm is a newcomer in the field of advertising.

Dictionary.com

Newcomer was my first thought but, depending on the context, incomer may also be suitable.

incomer Noun British
A person who has come to live in an area in which they have not grown up, especially in a close-knit rural community.

I've heard people out west say, greenhorn, though typically it means something equivalent to a rookie, it can also mean a newcomer usually to a rural area.

Greenhorn (MWD)

1 : an inexperienced or naive person

2 : a newcomer (as to a country) unacquainted with local manners and customs

Johnny-come-lately (MWD)

This isn't nearly as common as the other answers in this thread, but it's a colorful, American phrase and deserves mention.

1: a late or recent arrival: newcomer

2: upstart