As a historian, I am contractually obligated to remind you that the Thanksgiving story is a lie and relations between European immigrants and Native Americans have been mostly (though not universally) awful for the Native Americans.
Now that that’s out of the way, enjoy your turkey! No, really, I mean it. It’s okay to celebrate the idea of peoples of different backgrounds and ways of life coming together in peace and friendship as long as we remember that we’re celebrating a dream of how things could be, not a memory of how they were.
Or you can celebrate something else, like family and good fortune. That’s fine, too. I like to celebrate the fact that stuffing is delicious, but that’s just me.