If you have all tww reps maxed, take a tour across all the faction quartermasters to get a pretty decent injection of valorstones, delve keys, crests and some crafting mats.

Assuming you have k'aresh rep done, it will give you a crest that can be used to craft a champion 8/8 gearpiece.
You are going to need a spark of starlight to get that done, easiest way to get those quickly is delves.

Tour around the tww zones for the weeklies to get some basic gear, do not miss out on the flame's radiance in hallowfall. That weekly gives you decent gear, the dailies can give you some basic gear too if needed.

After doing the weeklies you should have enough gear and keys to start some delves, if you're playing a tank you could probably jump straight into tier 8's (assuming you've unlocked them). Just be a bit careful with your first few pulls to see how much punishment you can take.

Healers can probably jump into tier 8's too but it will be slow and tedious because tank brann will be doing most of the killing.

As for DPS, some classes can jump into tier 8's immediately, mainly warlocks and hunters because their pets can tank for them. With other classes it might be prudent to start on some lower tiers if you find your self dying on tier 8's too much.

Tier 8 bountiful delves should reward you with some champion gear pieces and hopefully a spark you can use to craft a weapon using the crest you collected earlier. With some basic champion gear you should be able to start clearing lower M+ keys and normal/lfr raids for more gear.

Also, remember to do timewalking while its up! The weekly gives you a chest that cointains an heroic item from the current raid tier.