Where should a miner get the most current block from? Where does a miner get the most recent/current block from, to work on confirming new transactions and building the next block?

Obviously it's the 'top' block on the blockchain - where can a new miner 'get' the blockchain from? As I understand it, it's P2P, but how do you connect to those peers in the first place?
You've asked two different questions and already answered one of them.

Solo miners get blocks from their peers on the network.

Discovering peers is done by a bootstrapping process. Basically, the software comes with a default list of known nodes, and from these nodes the client learns about other nodes. More details are at https://en.bitcoin.it/wiki/Satoshi_Client_Node_Discovery.