for really really really new players who just got Andro (or just Cassiopia - because you need her to unlock D'Art anyway), they can get ori wpns, which only cost 1 ori each and has unlimited stock. They are not great wpns but it does come with assault, so it can help a new player who doesnt have a full grid and needed the ATK for solo contents - which is needed to obtain mats for the ULT/RAG raids.
Light Ascension wpn
Water Ascension wpn
Getting 1 ori per GO is easily attainable - completing these gives you 6 pts - enuf for 1 ori.
Week 1
Challenge GO 3 times.
Challenge GO 5 times.
Clear stage 1 3 times.
Clear stage 2 3 times.
Week 2
Challenge GO 5 times.
Clear stage 2 3 times.
Getting Grace or Protect is actually easier, since joining any RAG raids has a chance to drop the phantom, and if you are spamming a ton of seeds, you will get them eventually.