There were a number of publications that went by that name, some quite informal (as in printed by units in Europe) and some much more regular. This one is fortunately pretty nice, so it's produced some hits.

Your cover type and style matches some known covers from The Mess-Kit, the serial publication of the US Base Hospital at Camp Merritt, NJ. Your specific number is not among the ones the NIH has, but it might be a place to start in terms of figuring out what the publication itself was.

As to what that text refers to, "number please" (or "what number please") was the initial query by a telephone operator to a caller, at a time when connections were made manually. This work fell to women, and there was an expeditionary corps of American women operators in Europe from 1918 to 1920. Thus the language issue was relevant.

By the way, if you look 1/5 of the way down the last linked page (j'ecoute), you'll see the exact same image that's on the cover of your Mess-Kit issue, from the Telephone Review of May 1918 around when the women shipped out, as a tribute from AT&T. I can't fully read the name (Archie something) but it's clearly about the telephone operators for the US Expeditionary Corps, so that's your reference. I'm not sure about the rest of the content--you'd need to scan the whole thing for us to be sure.

OP, it would be helpful if you could link to some photos of the paper. Or at least describe in greater detail: is this a newspaper? A piece of paper? How big? What's on it? Is it printed or handwritten?

You might also consider x-posting to /r/whatisthisthing