Directors cast one of two things - for acting ability/skills or for looks.
Your job is to show them what you look like, but also what your acting abilities and skills are. In order to do that, you need to learn how to audition, how to act, and how to best present yourself.
1.) Audition Technique. If you aren't good at auditioning, then no one is going to cast you. Your audition is the first chance they have to see what you can do. You can't learn to get better at auditioning by just auditioning. You have to put the work in - by yourself, in an acting class, and/or working with a coach.
2.) Acting Skills. You would think acting and auditioning are the same thing, they're not. Auditioning is your interview. Acting is carrying the performance for a longevity and is repeatable. You have to be connected to the character(s) you're playing and tell their story multiple times during the shows run or while filming.
3.) Physical Appearance aka 'Your Look.' This is one people assume is has to do with beauty, and that's not true. Some characters require a specific look. It could be their height, their hair color, body shape, etc. It can even the way they look with another Actor. We're telling a story and you want it to be believable by the audience.
We have control over all three of these things. The third one does have its limitations, but look at what YOU can control within it.
If you want to make it in this business, you need to learn how to maximize each of these three things to their greatest potential. There's no book, video, or podcast where you can quickly learn all of this. Taking an acting class AND working with an Acting Coach is honestly the best way you can learn and excel. Invest in your dreams and watch them happen.