Lightning uses actual Bitcoin UTXOs. However, they are owned by two people, instead of just one. That co-owned UTXO is a payment channel in which the owners agree on how much of the channel they are each owed when they decide to close it. This agreement is updated every time you make or receive a payment through that co-owned UTXO channel.

In order to make or receive any payments on Lightning, you must have at least one channel opened with someone, either by you locking up your own on-chain bitcoin into a co-owned UTXO, or asking someone else to lock their Bitcoin into a channel with you. In the latter case, they will usually charge a fee.

You should also be somewhat picky about who you open a channel with. The best channel partners are folks you can reach out to if your node is down, to keep them from force-closing the channel, and who are connected to the broader network via their existing channels.

After this, we can start talking about liquidity, and having the amount you want to receive or send available in the direction you want it to go.

Welcome to self-custody #Lightning!