why do i have to do quests to unlock decor? and if so, where do i even start?

hi everyone!

im relatively new to wow, been playing occasionally for a year, but i started playing more with midnight.

im trying to collect and find as many decors as possible, but even when i have the currency, they all say i have to finish a quest first. but i have no idea how to do those quests? like where do they even come from? so im exploring around for nothing?

i haven't seen a post regarding this anywhere.

and what other easy quests/tasks can i do to unlock as much decor as possible?

TIA and please be nice!!!