We recommend LOOT (or Vortex) to manage your load order.

Manual Load Order

Requiem is a major overhaul and touches many aspects of the game. Due to nature of such overhauls, it will conflict with many other mods which try to change content also modified by Requiem. Often, you will need dedicated compatibility patches to resolve these conflicts and you must load the plugins in the appropriate order.

In general your load order should look like:

Skyrim.esm
Update.esm
Dawnguard.esm
Hearthfires.esm
Dragonborn.esm
[esl plugins]
Unofficial Skyrim Special Edition Patch.esp
...
[all normal mods not depending on Requiem]
...
Requiem.esp
...
[Requiem patches and addons]
...
Requiem for the Indifferent.esp

Any plugin that doesn't depend on Requiem.esp should be loaded before it unless you have a specific reason to do otherwise.

At the very end of your load order should be the Requiem for the Indifferent.esp which you created as part of the installation process. Remember that its content depends on your load order and you must recreate the patch whenever you add, remove, update or reorder plugins. If you happen to have multiple mods generating automated patches (e.g. with Synthesis or DynDOLOD) all these patches should be at the very end of your load order. You'll have to figure out the appropriate order of these patches yourself, but usually the order doesn’t matter.