Welcome to the forums. In the future, please make a new thread unless your subject is about the same problem. I've split and merged your posts into this thread for you.
As for your saildrive, you need to identify the model, which is written on a handy type label on the top of the gearbox/saildrive unit, in the engine compartment.
On the 120S, the anode is a ring anode that goes after of the saildrive housing and in front of the propeller, like so (the shiny silvery thing is the anode):
If your oil is white, you have water in it, so you need to identify where that came from. The most common cause are perished seals at the prop shaft, so you need to remove the prop shaft and inspect them. There might also be wear on the shaft itself. On the 120 models, the oil drain plug is at the bottom of the leg, outside the boat, so you need to haul out (which guessing from your other posts, you need to do anyways).
