Regarding the weapon, you can purchase the Dawnforged weapon for Naryu silver from Zaiwei(might be a vendor in Mushin's Tower also), you may need to buy a few in order to get one with 8 gem slots, but keep trying.
Regarding the Accessories, one of the easiest ways to get the next tier up is in Moon Refuge, There is daily mission in there(part of the daily Challenge) and then the repeatable mission there also, The Daily mission will give you part, the repeatable you'll need to complete 4 times. Then you take that back to one of the vendors in Moon Refuge to exchange for Moonlight Buds, which you can in turn use to purchase ACCs.
Get on a Skybreak Spire(BT) dungeon team, plenty of teams taking lower characters and get the ring and earring from there. Don't buy with Buds it costs too much, i think they can also be bought from the current event.
As for Gems, you should get a few completing the quests(Temple of succession quest gives some also i think, not the raid).