- First layer wallet: 10% - 15% of my BTC in my mobile hot wallet (I love BlueWallet)
- Second layer wallet: ~30% of my BTC in a hardware wallet that connects to the internet via USB
- Non-circulating BTC: ~60% of my BTC in a cold storage air gapped device
You can classify it by your wallets for trading with Bitcoin and using Bitcoin for getting cash or buy goods, items and wallets for hodling.
I don't think classifying them to first and second layer wallets is good and correct in technical terms. Hot and cold wallets are more correct. Hot wallets can be used for trading and regular using for payments. Cold wallets are safer and more relevant for hodling.
With hardware wallets, you can use them for trading and holding too.