I understand you've posted this on the altcoin section and you're looking for an altcoin. But before getting that, do you already own Bitcoin. If not yet, that should be your first crypto to own and then follow it up with some top altcoins in that website and if I am you, I'll be mostly going to take Ethereum next after Bitcoin.
Everyone knows Bitcoin (BTC) is best of the best assets, no one doubts that. But @OP came here asking & wanting to hear something outside of Bitcoin (BTC). There's nothing wrong, he doesn't have to buy Bitcoin (BTC) before having altcoins.
To @nestor7777, I wouldn't recommend you buy right away after this, but I think you might want to take a deeper look at some of these coins/tokens first:
- Ethereum (ETH)
- Solana (SOL)
-
USD Tether (USDT) 
- Sui Network (SUI)
- Aptos (APT)
Above assets have good technology & have their own value in the market, DYOR before buying them.