Let's say you wake up one day and are all powerful but, to keep things interesting, you are not omniscient. You have no way of knowing for sure what the implications of your actions can be. You cannot be killed and you do not age. You have some reality altering powers but let's avoid boring ones like "i snap my fingers and all is good in the world". All humans have free will ...[text shortened]... this game interesting. Add some rules if i forgot any and you think would make it more interesting)
I'll just assume, as you suggest, that I suddenly have the powers of Superman.
Yes, I would make myself very busy. With such power I would not be half-assed about my agenda. I would...I would...
Well, coming to think of it, Superman is just a lunk. Physically strong, yes, with eyes that can shoot lasers and the ability to blow freezing cold air, but he cannot really do much that our current technology and machinery can do. When you think about it.
Now I'm casting my mind in the direction of the Harry Potter universe. What if I had the power of a Professor Dumbledore? Now we're talking. He's got limitations, but can change the molecular structure of matter and whatnot. He can reassemble a structure that's been smashed. So let's get busy...
First, it's unclear to me to what extent Dumbledore could sequester carbon emissions in soil, and if so, then by how much. I'd make every effort, but we're talking about millions of cubic kilometers of atmosphere. This might be a bust.
I would make frequent, clandestine use of the imperius curse to cause terrible politicians to say or do terribly stupid things, out in the open, to guarantee they lose power. A few weeks before an election I could make a Trump or a DeSantis say something that would absolutely destroy their chances of winning and give progressive folks a broad path to implementing progressive, science-based policies at all levels of government. In fact, if I retained my anonymity and did just this much in governments around the world, I could possibly (in a few years' time) enable humanity to help itself out of the hole it's in. If I reveal myself, then such a strategy could backfire. So, no fame or glory. I'd have to remain unknown.
Sabotage. Lots of it. Machinery will just keep breaking down wherever there's a bulldozer in a jungle, a tank or fighter jet on a mission of aggression, or whatever.
If a levee is breached in a hurricane and I magically reassemble it, the game is given away. But what do you know...it didn't break in the first place.
A quick search turns up that wizards in the Harry Potter universe can change the weather, at least locally. That 15% chance of rain where a Canadian forest fire is raging is the only pretext needed to make it rain there, and quench the fire.
Some people will find their cancers go into remission, or their infection clears. A miracle. Maybe this is Jimmy Carter's secret.
Doubtless I'm missing some really obvious interventions that could be done without giving myself or the existence of magic away, but I've probably diddled enough for tonight.