I'm assuming you've checked your owner's manual already?
Let me see if I understand your question. You want to know how to move the needle to a different position? Or you want to know how to change the default position so when you turn it on, that's where the needle moves automatically?
I also had an entry-level Brother that had the needle position return to default every time I turned on the machine. I just learned to double-check the needle position every time I changed to a different foot. Maybe write yourself a note and stick it on the screen.