If you had a time machine and unlimited resources, in what way would you unwisely interfere in the time stream? The Aztecs get AKs and smallpox vaccine? The Roman empire plus Communism? Solar panels at the dawn of the industrial revolution? Jimi Hendrix gets an iPhone? Introducing elephants to North America before people make it there? Go wild.
Idea 1: Kill Jesus while he was still an infant. Idk what this would do in terms of goals but history would certainly end up very different.
Idea 2: Prevent the invention of video games. Idk maybe this one would prevent the return of active fascist movements among jaded white young men in America somehow.
Idea 3: Kill Friedrich Ebert to somehow ensure Rosa Luxembourg successfully led a communist revolution in Germany?
Idea 4: Introduce LSD to the drinking water in Rome during the height of the Roman Empire. The entire city of Rome. Yeah. Also give LSD to Ghengis Khan, Empress Wu Zetian, King Henry VIII, Emperor Meiji, Charlemagne, and sure let's go with Xerxes and Mansa Mūsā to round it out. Don't tell them you're giving them a drug tho just slip it into their water while they're alone in a beautiful garden or something. If in this timeline American colonization still happens then LSD should also be introduced to the drinking water in Boston and Philadelphia like idk three weeks before the Declaration of Independence is written. I just wanna see what happens.
I would introduce COVID or something to the first English people who tried to colonize Ireland, as a deterrent. Ireland was the prototype for European global colonization, so I do wonder if it never took hold there, would it still take off elsewhere?