A:AnswerYes — you can connect the new iPad Pro (M5) to a speaker that only has a headphone jack.
The new iPad doesn’t have a 3.5mm port, so you’ll just need the Apple USB-C to 3.5mm Headphone Jack Adapter. Plug that into the iPad, then plug your speaker’s AUX cable into the adapter.
If your DJ speaker uses RCA or 1/4” inputs, you can still use the Apple adapter — you’ll just need a simple 3.5mm-to-RCA or 3.5mm-to-1/4” cable.
That’s all you need to get audio from the iPad into a non-Bluetooth speaker or DJ system.