Each of those modes existed long before this latest expansion; raiding is a basic concept in MMOs, and Mythic+ was added in World of Warcraft’s last expansion. The problems with Battle for Azeroth’s endgame come from the systems it adds, which most often artificially gate progress where most of the fun can be found. If raids and Mythic+ are the carrot, we’re about to talk about the stick.
You should try and quest efficiently - pulling several mobs if you can handle it, using your burst cooldowns while questing to kill everything faster. Many people would think that a 10-minute cooldown like Bloodlust is useless in open world, but you can do a "kill-15-mobs" quest in like 30 seconds if you pull a lot and use it. A free quest every 10 minutes is not that bad.
Mag'har orc - "For untold generations, the orc clans of Draenor battled one another in endless war. But when Gul'dan offered them the blood of his demonic masters, the disparate tribes of Mag'har—the orcish word for "uncorrupted"—refused the dark bargain and banded together to drive out the Burning Legion. United under the leadership of Grommash Hellscream, the Mag'har pledged to one day repay Azeroth's heroes for aiding their cause. As war against the Alliance intensifies, the Horde must call upon the might of the Mag'har to seize victory."
You can earn a decent amount of XP by doing Herbalism or mining. Any zone works but I prefer Sholazar Basin as a lot of the mobs are not aggressive and the mobs are spread out so you will find a lot of herbs and ore that you don’t have to fight for. It is possible to make about a level every hour by doing this, or a level every 30-40 minutes with rest XP.
Aegwynn-Alliance-USAegwynn-Horde-USAerie Peak-Alliance-USAerie Peak-Horde-USAgamaggan-Alliance-USAgamaggan-Horde-USAggramar-Alliance-USAggramar-Horde-USAkama-Alliance-USAkama-Horde-USAlexstrasza-Alliance-USAlexstrasza-Horde-USAlleria-Alliance-USAlleria-Horde-USAltar of Storms-Alliance-USAltar of Storms-Horde-USAlterac Mountains-Alliance-USAlterac Mountains-Horde-USAman'Thul-Alliance-USAman'Thul-Horde-USAndorhal-Alliance-USAndorhal-Horde-USAnetheron-Alliance-USAnetheron-Horde-USAntonidas-Alliance-USAntonidas-Horde-USAnub'arak-Alliance-USAnub'arak-Horde-USAnvilmar-Alliance-USAnvilmar-Horde-USArathor-Alliance-USArathor-Horde-USArchimonde-Alliance-USArchimonde-Horde-USArea 52-Alliance-USArea 52-Horde-USArgent Dawn-Alliance-USArgent Dawn-Horde-USArthas-Alliance-USArthas-Horde-USArygos-Alliance-USArygos-Horde-USAuchindoun-Alliance-USAuchindoun-Horde-USAzgalor-Alliance-USAzgalor-Horde-USAzjol-Nerub-Alliance-USAzjol-Nerub-Horde-USAzralon-Alliance-USAzralon-Horde-USAzshara-Alliance-USAzshara-Horde-USAzuremyst-Alliance-USAzuremyst-Horde-US
The most simple thing is TradeSkillMaster. This AddOn shows you quite an amount of information in the items tooltip. In my opinion, DBRegionMarketAvg the best source. It tells me the price, an item was posted on all EU realms in the last 14 days. Why not DBMarket? DBMarket only shows you the items value from your server in the last 14 days. This value often gets manipulated. Some people start to post an item with a 500g value for 500.000 Gold on the auction house for several weaks. As a consequence, DBMarket is rising towards 500.000 Gold. If you use DBMarket with 100% and post your item for 500.000 Gold, nobody will buy it.