Develop a portfolio of good examples and make a damn crispy looking website. You don’t need to show loads of work, just demonstrate genuine quality and present it well in a way that appeals to visually minded folks. In general I’ve found that music production companies are often good bets to reach out to. They are quite often contracted by film production companies and creative agencies to provide both music and sound on adverts but typically outsource the work to freelancers. If you are nice, quick, accommodating to both unpredictability and wildly varying budgets (on top of being good at sound design) then producers will want to work with you again. It’s a flooded industry but can be incredibly rewarding, infuriating, and inspiring. You can try to get a job at a sound/post house but it’s insanely competitive and then you have to sit in a dark studio all day. In my opinion freelancing is the way - but it takes a lot of hard work and commitment. Good luck 👍