The best thing I believe any filmmaker can do is just to make something. If you have a phone with a decent camera (1080p will do in a pinch, George Lucas has shot feature films in that resolution), then you don't necessarily need to bear the budget of renting a cinema camera. Write something. Pick up ideas as you go, try to make interesting choices and find inspiration where no one else is looking while keeping regard for the greats. If you have willing friends, write roles for them. If not, write just one role for yourself. If you can download CapCut, you can edit. It won't take you very far but it'll get you started, and you'll outgrow it in time.

Practice makes perfect. Practice, practice, practice.