If there is no inherent limitation in terms of complexity, this can become incredibly powerful.
The first few days would probably be spent turning something simple and abundant into gold, something like Nitrogen, simply taken from the air.
I'd then use these funds to get trustworthy people working on cyberware so I can upgrade myself with some high end memory banks and processing power, which will directly boost the scope of my powers to a whole new level.
It will also lead into the acquisition of more combat power (I like the slime idea people brought up, so maybe a special gel that can be linked up to the nervous system for a slime-tentacle-armor) besides the already potent power.
Parallel to that, studying a broad set of fields like molecular and atomic physics, chemistry and biology will boost the powers even without cyberware (who knows how long that takes).
I'd probably set another team to study how powers work and how people get them.
With enough understanding, transmuting my own body should also be possible, even if it takes a few days and prep time to ensure it doesn't break down during the process.
At that point, I'd probably start collecting more cool powers. That's probably the earliest I'd make myself known to the world as someone with powers, at least by choice. Ideally while keepinga bunch of powers, including the original one, secret, to not paint a target on my head.