You're doing great!
There are nodes at each layer of bitcoin.
Layer 0 node - People! The gossip amongst each other sharing stories and experiences. The most critical nodes of bitcoin. These nodes never truly sync and the consensus is super small in size.
Layer 1 node - The timechain nodes. These nodes maintain the ledger (or a portion of the ledger) aka blockchain and handle transactions. Thes nodes also gossip but mainly about the state of the network. Sharing transaction and block data amongst each other. Each node has it's own current snapshot of pending transactions (the mempool of that node) but all agree on historical transactions for the most part. The older the transaction, the more likely it's agreed upon. After about an hour, it's pretty certain that transaction will not change, ever,
Layer 2 node - Lightning! These nodes create channels between each other to swap small amount of sats back and forth. They'll also route payments among their channel partners. They take a small fee to do so. The biggest consensus piece of this is between two channel partners. They have to agree on the balance of their channel (who sent what amount to whom) and can go to the Layer 1 chain to dispute this. This is where zaps live.
Layer 3?? There is debate as to what constitutes Layer 3, but the debate is mainly among Layer 0.
Keep studying bitcoin! And continue to sync your Layer 0 node with others. :)