I'm not sure what do you mean by "fork litecoin". However, you could use Bitcoin Testnet network, so you don't need to experiment/learn with real money. You can use faucet (such as
https://testnet-faucet.com/btc-testnet/) to obtain testnet Bitcoin (tBTC).
I could be wrong with my terminologies, what I meant was I downloaded a copy of the Litecoin code and modified it to create an altcoin.
The term you used isn't wrong, but "fork" have multiple meaning on cryptocurrency space. Fork also could mean upgrading network protocol or creating new coin from current existing coin.
I know this is a Bitcoin forum but so far I am able to resolve issues with my altcoin "litecoin fork" with posts from this forum. I will look into your suggestion and set up a Bitcoin node as well to learn more about it. Thanks!
I'd like to remind that you'll need to download and store about 27GB of blockchain if you plan to setup Bitcoin Testnet node.