You and I can open a channel. You fund it with 0.001 BTC, I also will fund it with the same amount 0.001 BTC. Making 0.002 BTC in total.
To open the channel, normal on-chain transaction will be demanded for. To close the channel, also on-chain transaction fee will be demanded for. But lightning network dey useful for small shopping after you don open a channel. Like if the supermarket you dey buy provisions support am, or where you dey cut your hair weekly if they accept ham, you can open a channel with them, or open a channel with some that already open with them, like if you and I dey use the same supermarket, I open channel a with the supermarket, you no need to open channel with them again as you fit connect through me to the supermarket (but maybe the fee will be a bit higher, I do not know, but yet go still low though).
The channel you opened can be closed, you will pay on-chain transaction fee for it and your bitcoin will be back to your on-chain address.
If you dey use Electrum, you fit experiment it with two Electrum wallets, but BlueWallet makes it easier for newbies. To get more technical knowledge about it, Electrum is the best.