起動時、TextField にフォーカスを当てる

@FocusState を使用する

swift

struct ContentView: View {
	@FocusState private var isFocused: Bool // ← ★1

    var body: some View {
		VStack {
			TextField("placeholder ..", text: $title)
				.focused($isFocused) // ← ★2
				.padding()
			}.padding()
		}
		.onAppear() {
			isFocused = true // ← ★3
		}
    }
}

Bool でなくて enum でやる

swift

enum FocusInput: Hashable {
	case input
	case newTag
	case fixedTitle
}
struct EventDataInputView: View {
	@FocusState var focusInput: FocusInput?

	...
	focusInput = .input