I did my first gig as a sax-player after I'd been blowing for about five weeks. Fortunately it was with a band I'd been involved with on and off for about 25 years as a guitarist, and even helped write some of the songs, and 'sloppy' was the band's middle name, so although I was new to the sax I knew what to do, it was just a matter of remembering how to do it! And, I totally loved it, was sorry when it ended - I think that was the moment I got hooked on playing.
Playing at the first jam I went to was definitely nerve racking at first - these were real musicians (well, some of them) and I didn't really know any of them, but after a couple of choruses and some encouragement from one or two of the others on stage, I'd got over it and have always been ready to play since then, even though I know there are others much further down the road than I am, or maybe ever will be.