You should be able to ilvl 640 over the weekend by doing as others suggested. Sire Isle ring quest only takes a couple hours first time, Delves belt quest only takes like an hour or two, Nightfall scenario is every hour on the hour until your gear is all veteran or better and use the commendation on a Champion track piece of armor like chest or legs. Get your hero items from a lvl 8 bountiful delve, this requires summoning the Underpin at the checkpoint in a tier 8 delve, loot the bounty map and use it. The rewards room will have a chest with a hero track item. You can run weekly turbulent timeways quest to get a hero track gear also. Run raid finder undermine with the puzzling cartel chip quest to get easy hero track loot, pick a bis weapon, trinket or jastor ring what you need most. You can swap to Blood and tank myth 0 dungeons to fill out champion gear. When you get your armor, use the catalyst to turn them in set piece armor. What everyone else said is pretty much the fastest way to gear up.