Yep - but it depends a bit on your use case. A sandbox might still be the preferred way to go if you’re developing a smart contract though. But for a lot of other use-cases or just trying out some things, the public testnet is actually just as fine and saves some hassle.
You can use an explorer like Dappflow: Dappflow | Algorand Developer Suite or Pera Explorer to browse Testnet: https://testnet.explorer.perawallet.app/