Monitor scripts executing when loading a page?

I don’t know PHP, it has been a very long time since I’ve dealt with any of this so forgive my ignorance.

If I want to see what scripts run, or whats being called to run, etc. is there a way to do this? I am on a shared hosting provider so I can’t see much. The logs are not helpful.

I’m trying to find out what is eating memory/cpu usage. It will spike and then come back available after about 2 minutes so something on the back end is running when I open posts for editing. It comes up with a 503 error (we don’t need to discuss that at all).

Please don’t tell me to contact the theme developer. Please just help me to see whats going on.