I think they said they were going to open a new server every 2 weeks. So you'll just have to wait for your region

Mmkay well I'll share my thoughts.

Where to spend coupons?

In events that give you 6 paths Naruto fragments, then kakuzu fragments that also give you more than just the ninja. For example, this week Naruto is in time limited ninja recruitment. Don't spend there, because you only get the ninja for doing that

He has been in lucky stars or lucky board. Those events you get both the ninja (for roughly the same price) as well as items on the wheel or board.

Silver (assuming moon coins) ?

Cave keys. Get all the cave keys you can get and use 1050 or 2100 every cave key rebate to get an ultimate essence.

Gold (assuming sun shop)?

Seal scroll fragments or advanced refines. You need ninjas, you'll need to draw in the GNW, Jin 1, kage, and time limited treasures to start getting some good ninjas. Advanced refines, yeah you need a lot of those.

Ingots?

Only on Naruto froggy. Recharge when there are at least 2 different ingot recharging rebates or a kakuzu fragments available.

Other things to spend on:

Group shop points: medium refines, advanced refines, summon mystery gems (for pakkun, katsuyu, and ninja dog Shiba summon mystery)

Summons shop points: king of hell or summon runes

Mystery stones: mood scrolls

Space time points: medium refine, charm material pack, cave key

Power stuff:

Invest freebies from events in power stuff or working towards ninja fragments. (for instance if you are getting 2 dice from lucky board, use the points from those on the refine packs for advanced refines)

I agree with shark bomb, work on purifies first. Get 5 gold iniatives on 5 different equipment types (scroll, armor, head gear). Those are now your position 1 (p1) equipment. No matter your lineup, those will always be on your position one.

After you get that, work on getting your p1refines and charms up to level 10. Spend refines only when there is a rebate AND you have 500 refines to spend. Use as many advanced refines before you start using medium refines for your other positions. Also, get the equipment that has the highest int% to level 10 first and use purification breakthrough pills on this equipment.

Use cave keys to stack your p1. Have your other positions be at least level 6 but keep on stacking your p1 until it is all level 12s.

Treausre tools, get 4 golden ropes (or 1 gourd for your main) and use ultimate essences on your p1 tool.

Charms, get all up to level 6 and then go for level 9s on p1.

Get training pots, bells, bond scrolls, and cultivate scrolls when you can. For ninja assist, prioritize either gaara if you want to get 6 paths Naruto or onoki if you are going for kakuzu. In the mean time, tenten is a good option because she works for all elemental types. For the bond system, get naruto, sasuke, Sakura, and Kakashi up as those ninjas work well with most bonds. If you are going for jonin Minato, get boy Kakashi, boy obito, and jiraiya up as well. Cultivate scrolls get all up to level 10 to unlock the first one before going all the way up p1.

Hopefully this is more in depth for you.