You’ll need a place to store your litecoin, known as a wallet. You have a range of options, which impose tradeoffs in terms of security and convenience. The best balance is probably to download the Litecoin Core client. This will take up around 15 gigabytes of space since the client downloads the entire litecoin blockchain (unlike with ethereum, you can change where these files are stored, so it’s possible to keep them on an external hard drive).
The core is the most reputable wallet software for litecoin, suggesting that it’s relatively secure. It can be used to send and receive litecoin, making it relatively convenient. As long as it’s kept synced with the network, it also contributes to litecoin’s overall health: running “full nodes” (full, synced copies of the blockchain) helps to keep litecoin decentralized, whether you are mining or not.
On the other hand, if your priority is security, it’s best to keep your litecoin stored in one or more cold wallets – ones that have never been connected to the internet. People dealing with large sums of cryptocurrency sometimes generate key pairs on fully air-gapped computers. Others use paper wallets, storing their keys in physical form as QR codes or strings of numbers and letters. Some even advocate “brain wallets”: remembering a series of random “seed” words that can be used to recreate a private key.
At the other extreme are the exchanges, which provide the most convenient experience available to cryptocurrency holders. By keeping your litecoin on an exchange, you’re able to swap it quickly for fiat currency. Relatively, that is. Even the best exchanges experience frequent trading outages. Historically, cryptocurrency exchanges have been prone to massive hacks and spectacular collapse. Exchanges keep your private keys in custody, so while you might legally or notionally control your litecoin, you cannot move it. You can only ask the exchange to do so.