5 letter callsign is fine. The controller's accent was Russian
His name is Eugene.The LA ARTCC refers to the Los Angeles Air Route Traffic Control Center, defined here.
Here's a map of the US airspace, split into each of the ARTCC's:
PE will cover the ZOA and ZLA ARTCC's. Reference the 'WHERE' page on the web site for skyvector.com overlay for each of the facilities.
You'll cover ARTCC's in more detail if you begin your r/w instrument training. For now, though, that map should be helpful, along with the knowledge that if you refer to an airport's details on airnav.com or skyvector.com, you'll see a field labeled "ARTCC". If it says Los Angeles or Oakland, that means that it's within the PE service area.
Let us know how you do with the testing!