The topic of Covenant swapping is one that has surprisingly not been discussed much over the course of Patch 9.0.5. However with a good bit of Covenant tuning and changes coming in Patch 9.1, I feel it's something that should certainly be discussed. While you are able to acquire Renown through a wide array of in-game activities, there is most certainly an "optimal" route that you should follow if you are looking to complete the grind as soon as possible. There is also the option of leveling every Covenant to 40 Renown if you don't want to grind out those levels before 9.1's release. If you are interested in optimizing your Covenant swap while also learning a few "tricks" along the way, then you are in the right place.
Joining a new Covenant for the first time can be a daunting task. You have new followers, quests, missions, building and a large, empty anima tank to fill. There is also the small task of leveling your Renown from 1-40 which can surprisingly be done in a few days depending on how much time you invest.