try to ask your question in just one spot, I see all the posts on here so more or split up isn't necessary.
there should be a blinking ring at the top of the store shelf when you walk in, you didn't see that? If you did and you interacted with it, then you need to go to Roger (the big guy clerk there) and buy the meal kit. If you're still having issues and are playing on PC make a save at the store and, if you're on discord, send me your save and I can take a look at it.