on my ip there is a red cap with oil written on it.when do i have to fill it and with what.how do i check level and know if it needs more,does it need to be drined occsionally?how?

There is an overflow port on the side of the pump. Remove the bolt and fill with oil until it trickles out. It's been a long time since I worked on the 220D engine but I don't think there is a drain plug. Use a turkey baster to suck out the old oil/oel.