There was demand for a straightforward and simple guide of this nature, so here it is remade as a post for the opportunity of greater visibility.
Get LTC on Coinbase (or Coinbase Pro for lower fees)
Create a Monero wallet in Cake (or Monerujo if Android) - make sure to store your 25 word seed safely and offline (preferably in multiple secure places - DO NOT store your seed digitally without encryption!!!).
Click the 'Exchange' button in the lower right part of Cake (while in the Monero wallet) - pick From LTC -> To XMR.
Get an LTC address in your coinbase account (it should start with L, M, or ltc1...)
4.1 Paste this address into the return field in Cake
4.2 Fill in amount of LTC to exchange in Cake (make sure that the exchange rate to XMR is suitable for you)
Submit order and send LTC to displayed address.
Wait for everything to confirm, and XMR to be deposited to your wallet.
Voilà - Welcome to the world of effortless and private P2P value transfer (aka Monero;)
If there is any detail that I have overlooked or isn't fully clear - feel free to ask. Input on how to make the guide even more newbie-friendly is highly encouraged)
EDIT/ADVANCED DISCLAIMER: This method is optimized for simplicity, not perfect privacy. Any Fiat->Crypto on-ramp that requires KYC (like Coinbase) is suboptimal in regards to strings (see comment below for details). Whenever possible always try to participate in P2P liquidity instead of acquiring from regulated centralized entities (as in: localMonero, your social circle, people in crypto-meetups VS Coinbase, CashApp, etc...)