It’s not the only way to get hired here. Many have been successful without doing interview prep.
For me - having been without formal interview prep in my career it helped....somewhat.
I did Emerald Coast. I did a couple webinars as well as went thru the course material. It is very much geared towards the military crowd, but a good deal of useful information.
If you chose not to do the prep then just go thru the gouge and be professional and personable. Show that you care about customers and co workers. Know the values and have a smile on your face. Want to work at JB.
Half of the battle is getting the interview. I spent 6 years applying and finally got on here in the summer (even then only with a BlueDart). They want people who want to be here and will likely see thru those that are looking for a stepping stone.
Good luck!