There's this axiom around the entertainment industry that you never get the second chance to make a first impression. The thinking is, if you're an aspiring filmmaker, you should make your first shot your best shot, because people are very quick to develop lasting opinions about you based on the first thing they see, and you don't want the stigma of "that guy who made that one awful movie."
...While this is true to some degree, because people can be very inflexible in their first impressions, I don't think it's any kind of principle to get hung up on or live your life by. Of course, I don't think you should NOT try to make your first film your best film, because who knows, you could die tomorrow. But in terms of having a successful "career" (and I use the term despite the nauseatingly anti-artistic taste it creates in my mouth), I don't think it's any kind of dire situation if it happens that your first film isn't wonderfully received, and the simple reason is this: Kid Rock.
....Kid Rock is currently a talentless suck-ass rich and famous rock/rap star. But before that he was just a talentless suck-ass white rapper, and everybody knew it. That is, everbody who was pop-culture-attuned enough to know that there were some white guys trying to cash in on the hip-hop bandwagon by making miserably dinky records back in the 1980nothings. He was an unpopular joke, a guy whose name would be forever associated with some of the most worthless music ever made by humans.
....And then....in the 90's....everyone forgot about it! Kid even got a "Best New Artist" award at some kind of crackpot recording industry function. His music was still lame, of course, but now it was lame and LOUD and POPULAR. It was as if a collective popular amnesia struck, and no one called him on the fact that he had already had one shot and blown it by creating music of awesome feebleness.
...So that should give everybody hope. Even if you're really really bad in a public way, sometimes the public forgets about it and gives you a second chance to be just as awful, except the second time they reward you with an ex-Baywatch actress. Imagine if he had come back the second time with a record that was really good? Now that would have been something.