Depends on your power and on your level in rune stones, charms, refinements and magatamas and if you are f2p or not. Tell us those infos and we can help you :-)

I would suggest, given your situation, if you didn't do it, to bring your main character mood to +45% and the other 3 main team ninjas ones to 25%. After you did this you can bring to level 3 your main tactic (to 4 if you rank up tactic soon by luck) and with what is left you fully go in lucky board and with your redeem points you go first for charm packs and after it for medium refinements (in the range of level 4-6 charm packs give you a very good power boost/coupons spent ratio, but remember to use the charms only when there's the rebate). In the meanwhile you gather cave keys from events/wish tree and when you hit 200 you use them in the rebate.