At first I’d be like Fry in the episode of Futurama where he does “all the things I ever dreamed of” which amusingly turn out to be things everyone in the future has done and thinks of as pedestrian - riding dinosaurs and blowing up planets.
I’d make myself immortal and invulnerable as a precaution. And give myself a general health and attractiveness makeover.
I’d dabble first in Earthly delights perhaps - money, vacations, sex, drugs, since they’d be both free to me and consequence free. Maybe secretly grant some wishes to loved ones.
I wouldn’t use my powers to hurt anyone, because frankly I wouldn’t enjoy it. At worst I might play some harmless pranks on those who were especially dickish. I’d be very careful about hoarding my willpower to take away anyone’s free will.
I might make some changes to the world, but I’d try to do it in small ways lest there be unforeseen consequences, or changes too big make the world unfamiliar.
I’d give myself a bunch of superpowers - flight mainly, but also invisibility, intangibility, size change, and various super senses. Maybe shape changing.
Then I’d do a reality version of wiki browsing. Visit various time periods, places, other planets, answer all the big questions and mysteries.
I’m sure along the way things I can’t imagine would lead to opportunities I can’t yet foresee.
Eventually though, I predict that all these powers and experiences, though they were amazing and fulfilling in their own way, would ultimately put me out of touch with reality and humanity. When you can do anything at all, eventually nothing you do is meaningful. We can already do anything we want in dreams, but it isn’t as fulfilling. And when you are more powerful than anyone else by such a degree you become in s sense utterly alone.
Which is why, in an ironic way, I think my life and anyone else’s is kind of indistinguishable from the inevitable end scenario of any theoretical entity of limitless power. I think any God like being would eventually start to crave the things Gods don’t have access to - companionship and a sense of meaning and purpose. They would have to finally create a universe into which their consciousness could eventually split and attach to naturally evolved sentient beings in order to experience these things. And then I suppose the cycle could start again