I have an 05 wrx and I am at 15,200 miles and haven't had a chance to do the 15k service. I won't be able to take it to service for about 10 more days where I will probably already have 16,000 miles.
Does this hurt the car at all?
Should I try to ride it as less as possible?
Thanks and pleeeeeease don't flame me for my newbie question!!

No biggie. Just do it when you can.

Look at the maintenance schedule in your manual or on the Subaru website. The 15K is just an oil change and a bunch of inspections. The mileage interval is approximate, it doesn't matter if you exceed it by several hundred miles or even more.