Use your Essences

Essences in Shin Megami Tensei are kind of like TMs from the Pokemon games—they’ll let you improve and embellish your party’s skills. By using them on either your protagonist or your demons in the World of Shadows (which will appear at the Leyline Fount save points once you’ve made enough story progress), you can learn spells that help round out your party’s elemental coverage. You may feel tempted to hold onto your Essences in case you need them later, but I’d strongly advise against this.
Shin Megami Tensei V gives out Essences like candy. You may have difficulty grinding out a specific Essence in some cases, but generally speaking, you’ll only find progressively better Essences as you progress. By the time you’ve spent only a few hours in Da’at, you’ll already find Essences that outclass the ones you started out with. Don’t struggle trying to make your party’s default skill sets work; use what you got to flesh out your kits!
Remember, Demons can pass on skills whenever you fuse them, including ones they’ve learned via Essences. Additionally, as you advance the main story, you’ll have the option of buying Essences from the Cadaver’s Hollow shop. Vengeance even marks Essences you can purchase with a distinct symbol (pictured above). So if you’re the type who plays Final Fantasy games feeling too afraid to ever use a Megalixir, that should ease your anxiety.