My advice would be to line up 10-20 interviews that you absolutely don't want. Jobs that are too junior for you, jobs that are a terrible fit culturally or ethically. Companies you wouldn't be caught dead working for. Then just march in there and get practiced at interviewing. There's no pressure, you don't actually want the job; you're just there to get really good at doing exactly that. Spend a few weeks doing this, have a job interview every evening after work, or every day on your lunch break.
Later on, apply to the jobs you really want and it'll feel like a walk in the park. You'll be a pro at it.
I personally still do this to this day; a decade into my career. I'm on the job hunt right now actually. I had 3 interviews yesterday and only one of them was real. These days I like to mix it up, and have at least one warm-up interview the same day before any big interview for a position I really want. Practice makes perfect.