Pump...........
On top of the oil pump, you should see a small screw. You loosen it up till oil seeps from it.
If you can't find it or it doesn't have one (it is old), then try getting a rag, putting under the big hose and pull it away just enough to get all the air bubbles out. Then, put it back on.
Run your first tank of gas premixed with 40:1 oil. Your specified oil. No TCW-3 oils............by the time you go through that tank of fuel, the oil pump should have primed itself.