When I was teaching bass lessons, I'd often have friends, usually also in their mid-20s ask me, "Could I still start learning to play an instrument?"
My answer was, "Yes, but you probably won't be any good. Not because you're too old to learn, but because if you had the right inclination to be good, you'd have already found your way to an instrument." (This is totally different from learning additional instruments later in life.)
Learning to play an instrument creatively (as is your stated goal) is a long process of learning to build up intuition both about the structure of music and the way your instrument works, both mechanically and harmonically. Most of that happens in your head, not in your hands. There are methods that may be more or less efficient, but they all require years of effort.
That said, playing an instrument is fun. Learning to play a few songs on the guitar or piano is a totally attainable goal for a few months of effort. Really, something equivalent to that (including, e.g. middle school band class) is where most people get started. That remains fun even if you don't get to the point that you're using the instrument as a creative outlet.