lightyears is a measure of distance not time.

exactly, so when you look at star 10 million lightyears way that mean its taken 10 MILLION ******* YEARS for the photons to get to your ******* eye meaning you are looking at it 10 million years ago. LEARN TO SCIENCE

You should probably do a little more research
most stars live longer than that.

Like myrtille said, you're just wrong. Almost all stars have a life time of more than 100 or so million years, unless it is an EXTREMELY large star. And since we can't see individual stars with the naked eye from galaxies that are a hundred plus million years away, and a supernova takes so long to happen (relative to a human lifetime), it's very unlikely that a star you're looking at has died that recently. Oh, and if you're talking about a average sized star like our sun, then the odds are even more unlikely because they live for billions of years.

Welp, now I feel prepared for my Astronomy final this Thursday. /lecture