You will probably want to just reach level 380 and then buy a 380 primus weapon with decent stats in the market. For general use you just need to get it to transcendence level 5 or 7 MAX (there’s a transcendence discount event when rebuild hits), anything beyond that is inefficient and better spent on buying yourself a velcoffer weapon instead (better if you farm it yourself if you can, but buying it from the market can be more manageable if you don’t have a set party to do velcoffer with). Enhancement won’t matter as much in Re:Build so a +6 up to +11 is enough.
A lot of transcended primus gear are popping up in the market for a lot cheaper than what it takes to make them, so if anything just saving up as much silver and blessed shards as you can is the best thing to do to catch up.
EDIT: The 2x pract gear are best turned into ichor to put into velcoffer so you can still finish farming that up if you want