I clean my bobbin area after every 3-4 bobbins. I stack the empties in one area as a reminder.
Changing the needle? Yes, but not as often as I probably should. Find a cheap source and it is less painful to toss what appears to be a good needle when in reality it is probably past it's prime LOL
Check your manual for oiling or not... my machines are self lubricating :D:D:D