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 ***** 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