It killed humans, therefore it was a weapon. But radiation killed humans, and a medical X-ray machine wasn’t intended as a weapon. Holden was starting to feel like they were all monkeys playing with a microwave. Push a button, a light comes on inside, so it’s a light. Push a different button and stick your hand inside, it burns you, so it’s a weapon. Learn to open and close the door, it’s a place to hide things. Never grasping what it actually did, and maybe not even having the framework necessary to figure it out. No monkey ever reheated a frozen burrito.

From The Expanse book series, I feel this quote pretty accurately represents the possibilities of humanity interacting with such technology.

Very roughly speaking, 100.000 years ago our ancestors were using flint stones to hunt and do stuff, that was rightfully so considered peak tech. What would you think our ancestors would do if they suddenly got their hands on, say, a smartphone or a smart doorbell? Or maybe a ballistic missile or, say, a tiny little stent? Even their most cultured people would not know what it is, or how to use it.

So, what would happen if we suddenly got our own hands on a 100.000 years more advanced tech? Probably not much. We may not even be able to realize there is something worth looking at. And the few that may realize there is something there, say out of some intuition or because they're somehow that smart, would probably be considered crazy ;)

All that we could understand would immediately be used to improve weaponry,and pornography.

Sufficiently advanced technology is indistinguishable from magic.

Do I know how to use the technology?

I would hope that in 100k years, assuming humans are still basically human, the tech would be user friendly enough I'd be able to use it.

I'd want to try and improve the world with it. Give free power and clean water to poor countries. Help with medical research.

Hell it might come with a built in library so I can download that to researchers.

Doomer perspective: It wouldn't be alien at all. It'd be rocks. Literal, honest to goodness rocks. I could go out to my driveway and pick up a few of them right now.

Optimistic perspective: The tech is a do-what-I-mean machine and can do basically anything and everything, or else is capable of upgrading the user to achieve their fullest potential.

Combo perspective (told through ancient memes): 1) Any sufficiently advanced technology is indistinguishable from magic. 2) Power corrupts. Absolute power corrupts absolutely. 3) Do not meddle in the affairs of wizards, for they are subtle and quick to anger.

Assuming there is no irreversible collapse, technology from that far ahead is going to be basically god-like. If you play your cards right, there is no practical limit to what you can achieve.

Governments may force you to mass produce that against your will

They may certainly try.

that all depends on if we survive 100k years. that tech may be rocks.

100 milenia, that's long enough to forget everything, start over a bunch on times and still go much beyond we have.

Depending on what it is its unusual properties could go completely unnoticed or hidden for decades and then we might not have the technology to properly analyse it for a few more decades. Think an unbreakable string or a flashlight that apparently never runs out of batteries.

We would not understand how it works and likely destroy ourselves trying to find out.

Try DMT, that should answer some questions.