
Applying in the Dark!
I heard it’s better to say that I’m willing to work in all jobs at Costco but wouldn’t that make me look like someone lacking career direction? My goal is to show enough flexibility and interest in the job to get my foot in the door without misdirecting what I’m actually willing to do. I tried looking online for job openings at stores in my areas but Costco doesn’t list that information on the website so I have no idea what positions they are actually hiring for.

My two cents, I like your approach. I think saying something like "I am interested in working at Costco for the long term. I like the company and believe I can offer a lot of value. Ideally I am looking to work as XXXXX. But I am willing to start in any position so long as there is internal mobility potential. I am very happy to bet on my ability to outperform"
Something like that goes a long way. Focused goal, short term flexibility!
I also like idea of getting all in online but stopping in direct to talk w a local mgr as well. PIlite persists ce goes a long way.
Good luck!!
Fred

Apply only for the position your interested in then go to the store and ask to speak to the manager about your application status.
I understand what you're trying to say when you say that you're willing to "work in all jobs," the sentiment is not the problem it's how you're saying it. How about next time you say something like this, " I want to train in all departments of Costco so I can better contribute to Costco's mission of customer service. Also, learning various jobs will prepare me to take a place in management at some point in my career at Costco." See what I've done is not sounded desperate, but instead eager to learn and move forward, and up. GOOD LUCK.