Very basic tips:
Always save energy for special 10 pulls "Pact of Truth" events that guarantees S+.
DO NOT USE "Pact of Fate" with energy.
Don't waste energy on "Companion of Truth" pulls (for now). 95% of Companions are useless. I'm mostly using ones from events, and upgraded others from coin "Companions of Fellowship" pulls.
Save coins at start for Job upgrades. Although you could spare a few to get some Companions from "Companions of Fellowship" early on.
Chapters 1-30 are beatable with what you have, but make sure to always run Metal Zones until you level cap your characters to limit. This is key to beating most stages.
Schedule for Metal Zones
here and calendar for Monsters/Item bonus days
here. (you probably won't bother with that one until you beat story and start farming)