why does lp have light surface scratch after play?

I vote for paper scuffs.

Did you notice this scratch immediately after playing the record or did you pull it out to play a second time, and then notice it?
If the later, it could also be that when you put the record away after the first playing, that the paper sleeve scuffed the record.
(That is one of the reasons for discarding every $^#%@$ paper sleeve that the cheaper record companies use. Another reason being that paper leaves behind paper residue, whereas plastic coated sleeves do not.)

Other than that, Doug is correct that if the stylus did not leave the groove, and run across the record, that it could not have scratched the record, and you must have done it some other way. (Is it possible that you did not notice it on first playing?) (Another remote possibility is that the tonearm leads are hanging down low enough to drag across the grooves, which would be very unusual as well.)

Good Luck solving your mystery!

Did the arm skip across the record?

If it did, many things could be at fault. I wouldn't trust any professional installation these days. The number of shops who actually know their way around a vinyl rig is much smaller than it used to be. Learn to adjust your rig yourself. Vinyl is not plug-and-play, things are always changing and you need to learn how to deal with them.

If the arm didn't skip across the record, then you scratched it some other way or the scratch was there before and you didn't notice. New 180g vinyl is no guarantee of perfect vinyl.