Typically as a healer, you just want whatever gives highest item level. This is even more true after the newly discovered prorated ticks surrounding your raid legendary. As there is no longer a haste breakpoint to reach all stats are incredibly close. All of our secondaries are incredibly good but they do start seeing diminishing returns when hitting 30% so keep an eye on that.
For raiding: Intellect = Haste > Crit = Vers = Mastery
For m+: Intellect> Mastery> haste > crit > vers
Take into account that Mastery is your best healing stat for m+ but provides no damage increase so balance your stats around what you need more.
Intellect: Increases your spell power, which will boost your overall throughput.
Haste: Increases attack speed, spell casting speed and energy regeneration.
Mastery (Mastery: Harmony): Your healing is increased by a percentage for each of your Restoration healing over time effects on the target.
Crit: Chance for extra effectiveness on attacks and heals.
Races are a very minor thing and there aren’t many options for druids.
For Horde, you will most likely want to be Troll for the extra haste during your ramp, druid already has a lot of mobility built-in especially with the Night Fae ability so you shouldn’t really need the Highmountain Tauren racial for raids.
For Alliance races you will most often want to go Night Elf just for the utility it offers as the others aren’t that appealing.
Gloves: Enchant Gloves - Shadowlands Gathering (optional)
Bracers: Enchant Bracers - Eternal Intellect
Intellect Gem: Leviathan’s Eye of Intellect
Haste Gem: Quick Jewel Cluster
Armor Kit: Heavy Desolate Armor Kit
Oil: Embalmer’s Oil
Health Potion: Spiritual Healing Potion
Flask: Spectral Flask of Power