I think you need to break the concept of a wallet. The wallet is a piece of hardware (or software) that protects your private key to your cryptocurrency address.
A hardware wallet is more secure because its designed in such a way that your private key only exists on the hw wallet. Whoever wants send crypto from that wallet has to have physical possession of the wallet to send it.
A software wallet is less secure but more useful in that it can be installed on your cell phone, but then again, your phone is more of a risk because it can be hacked, stolen, or broken.
the typical path for people to "buying and selling" crypto currency is to find an exchange that they can transfer USD or ARS or what have you to. Exchanges are like... Coinbase, Binance, Ripio, etc. Once bought you can then transfer the crypto to "cold storage" which is usually your private wallet. this wallet could be a software wallet or a hardware wallet. From there you "hodl" the coins until they appreciate in value until you want to sell them. In which case you transfer back to an exchange, sell, and then transfer the proceeds in USD or ARS back to your bank account.