iphone 7 plus screen is separating from the top a little? what should i do? never dropped it

Honestly the only thing to worry about would be if the separation was due to something you did. Dropping it for example. Or it somehow the case you may have used caused the problem. But I suspect it is a quality control issue that slipped by and they will replace it. You won't know until you have Apple look at it.

I have the same problem... but mine is much worse there is a huge gap on the bottom right corner and the whole bottom... I never dropped mine either and there is a “clicking” sound when touching the left bottom side... mine isnt that old either

I would recommend taking it to an Apple Authorized Service Provider to be evaluated.

Assuming the separation isn't from accidental damage on your part, yes.

Contact Apple. It's the only way you're going to be able to move forward on this.

If Apple swaps it out, you'll get a refurb.

You said that it's only two days old. Get your money back and repurchase an iPhone. That way you'll have a new iPhone.