It takes a minute or two of running to get oil out to the rocker arms.

Here is what I would do:
Add a mechanical oil pressure gauge or confirm that the oil pressure "idiot light" works, then start the engine, confirm that it is getting at least 15 psi of pressure. (the light goes off at 15 psi)

Remove the valve cover & pour a little oil over all the rocker arms if they look dry. Start the engine and inspect for oil flow at the rocker arms. double check the valve lash adjustment while you are waiting.

Recheck to be sure that you still have at least 15 psi of oil pressure after warm-up. If no oil comes out of the rocker arms after 2-3 minutes of operation, shut the engine off and remove the lower rear head bolt. Restart the engine to see if oil is getting past the cam and to the head bolt hole.
DD

It maybe as a result of that if the choke was shut, or it could be the fuel pump has a leak in it's internals. It would be best to replace the oil.