I dove for years with leaking masks. After countless dives with mask leaks I finally found a high volume mask that does not leak. That said, if you are new it may just be you. No offense, there are just some discomforts in diving that you will get used to.
As for your mask, when you clear tilt forward and see if any water remains. If not, and then there is, well, its leaking.
Try wiggling your nose, smile, wink, anything that causes facial movement and see if the leak rate increases. If you can isolate where you can then look for a mask that seals or flexes better in that location(s).
Also, when you try on a mask at the store make sure you use a snorkel or reg to deform your upper lip in the shape it will be when you dive.
And when you dive the strap should be pretty loose. Mine always comes off during backrolls but the mask stays put with hand pressure. Too much (which is not much at all) will cause the skirt seal to deflect from its intended design. And you'll get a head ache!!
Good luck.