Previous games needed?

[Torasko]

Do I need to play the original games before starting this one? Or is it more like Final Fantasy where each game is its own story?

[Rezonus]

They are there own story.

[Ponyeater]

Except for the first few, the Shin Megami Tensei games are all stand-alone self-contained stories. Yet they also are connected.

SMT is a legitimate multiverse, where the base setting is a great cosmos, the Amala Network.
All games can be linked, so you occasionally meet heroes and special guests from the other games, like ghosts floating through the network. But each story stands on its own in the end.

So to answer your question - You can safely start with this one. And if you ask me, SMT V is the most accessible and great for beginners. You have many more options to shape your party and adjust to the difficulty spikes.
Compare with SMT Nocturne, which was 24/7 cck and ball torture ASMR central (but that's why we love it).
SMT V has a few "oh sh" moments, too. But they're far and few between compared to the earlier entries. Enjoy.

[Torasko]

Amazing, glad to hear!