Blizzard has added an insanely fast way to gear your alternate characters. All you need is to talk to a vendor in the new zone.
As World of Warcraft: Shadowlands hit its 9.2 update, players returned in throves for the new content. A new raid means a new tier of gear (including sets this time!), another zone to conquer and epxlore, as well as more ways to catch up your alts. Blizzard added another way to gear up your alts, and even though it's not a high iLvl, it's an extremely easy way to outfit either a forgotten character or a freshly level one.
How to gear your alt fast in World of Warcraft: Shadowlands
Once you've unlocked Zereth Mortis on your main, simply go to Haven, the main hub in the zone. Speak to Hadja, one of the many vendors there (ignore the quest, as it isn't related). Hadja offers "bind on account" gear tokens that any of your characters can redeem.
Hadja sells gear for Anima, which you probably have in large excess by now. Every gear piece sells for just 500, so that's not even a lot by now. You can get a redeemable token for every slot: weapons (1H or 2H can roll from those, so you can buy a few), trinkets, rings, pants, and so on (make sure to scroll to page 2). Buy a bunch, mail them to your alt character, and that's it.
My toon has redeemed all of her gear tokens, easily reaching iLvl 226. That's a good start to get going into Zereth Mortis!
What should you do next? If you already have a main character that has unlocked flying, spend a lot of time in Zereth Mortis hunting Rare mobs and finding chests. A lot of them have iLvl 236 gear. That's a great start to funnel yourself into one of the three main activities (Raiding, PvP, Mythic Dungeons).