Engine trouble- Plummeting oil pressure

So I took my demon out today to pick up my kid. I had just pulled up to the garage to park it when I noticed it was idling really low, about 500rpm or so almost stalling out. The engine was making some not good noises and the oil pressure had dropped to almost zero. I pulled in and parked it quickly and shut it off. The oil pressure hit about 20psi while pulling it in. It's a 360 with J heads an LD340 intake and 600cfm edelbrock. I've never had the engine apart so I don't know much about the internals. I'm wondering how to proceed. I was planning on draining the oil and cutting open the oil filter to check for metal shavings but once that's done I'm not really sure how to proceed. Hoping to get some info on what else to check and how to proceed diagnosing the problem. Thanks in advance!