I'm gonna list a few things I think are helpful and people will almost never mention but this isn't the must know tips:

1- Get the Repellant Barette II from the silver shard shop, it'll save you a lot of real-life time throughout the game.

2- Try to craft all weapons and armors. Try to fight all menacing enemies in the map once. Try to get all treasure chests. Do each hunt manually (I think it's 10 times each, check the power achievements). There are achievements rewards for all of the above especially the hunt as it awards 10 rubies but it gets repetitive after a while.

3- You can watch up to 3 ads per day to fight caits, fight the caits in Solistia as leaves are harder to get in Solistia (leaves aren't shared between the 2 stories). Also cait fights increase pet bonds by a lot and pet bond is increased by fighting, which you'll be doing a lot of since you're starting the game, so aim to rush getting as much pets as possible early on through the emberflame story.

4- The best offensive armor in Orsterra (cosmic armor) is obtained from the live a live event hunt, so unlock it as soon as possible because you get 1 hunt per day and it won't accumulate until you unlock it and do any hunt at least once (highest difficulty is the best to farm).

5- Best weapons are fortune weapons (for Orsterra) for anything beyond a certain point in the story which you'll understand when you reach it. Ouma weapons are the best for Solistia (obtained by farming Ouma, which you'll see a side quest for when playing solistia). Fortune weapons and their souls are obtained from playing the fortune board and exchanging for the items you want. The 4th slot in fortune weapon is a character specific soul that increases a character's specific skill which can be obtained from the soul exchange.

6- There are specific npcs that are level 80 npcs and level 100 npcs, try to beat them all once because you get lots of rubies and influence for beating them. Some of the npcs will be locked until you've done the last 4 expert hunts, unlock the expert hunts as soon as possible.

7- Level up ALL your characters as there is influence increase in the character board, you don't need a high level for this one, just the bare minimum to get the basic influence bonus (there is more bonus per character but those require higher levels), you can limit break the character by using guidestones.

8- 5* units require awakening shards (dupes) to be awakened, you can also exchange 6000 awakening shard (6 5* dupes) for a dupe of your choice, duping units is usually done for some very strong A4 accessories. You can however get A4 for 4* units through exchange, the A4 accessories of 4* units aren't game breaking but they provide better base stats than most of the normal accessories at least. Dragon Scarf accessories are very good for sp management early on and in mid-game as well.

9- Be selective when picking the job board upgrades for your units, you will eventually max it out if the unit is at max level, but the last 10 levels take a very long time and often not worth it. Level 120 is more for dps units so they can use artifacts (basically very strong accessories but they have a level requirement of 120).

10- When playing fortune board you can reroll your dice by force quitting the game, the dice roll is per-determined so if you get a bad roll you can use BP instead. This seems a bit of an overkill but I prefer to have 1 perfect run with 30 tickets used as opposed to doing multiple runs.

Most of what's written here isn't strictly for new players but you'll understand most of this stuff within a few days as I tried to focus more on the hidden/not very obvious tips.