One achievement a day and you will take forever to complete them
Bang out Taming Azeroth, assuming you have the seasonal summer and winter pets. Pandaren, Fabled Tamer, I choose you. A lot of the pet battle ones can be done in a single day. Finish up Loremaster and you will get Justly Rewarded from doing it. Bloody Rare and Frostbitten are easy to do as well, just pick up NPC scan or map it out with wowhead. Finish the Pandaria section of explorable achievements. The only one that might be difficult is the finding the pandaren artifacts on timeless isle as they have a lengthy respawn. You have a lot of profession achievements you can do easily, like cooking. You can also do a bunch of achievement runs for MoP raids to get the glory of the raider achievements.
It's a lot to throw at you at once but you gotta do multiple a day or you'll be behind forever