You need a GPU for ETH and an ASIC for LTC.

Maybe just start with your normal computer.
Add a GPU like AMD RX 5600XT or RX 5700 or NVIDIA GTX 1660 Super or RTX 2060 Super.

The Futurebit Apollo can mine LTC.
https://bitcointalk.org/index.php?topic=4974036.0

Then you need a wallet to store ETH and LTC.

For mining software, pools & calculators you can have a look at the app in my signature 

Take one of the biggest mining pools like ethermine.org for ETH and litecoinpool.org for LTC.