If you’re playing a high difficulty version of modded Skyrim SE (like I am), and especially at lower levels, seeing the level of your enemies and their hit points (health) can be very beneficial. This mod works on its own, meaning that you don’t have to use other mods with it, but it’s also compatible with certain UI replacers which I will link down below.
If an enemy out-levels you by 10 levels or more, the color of their level indicator will turn to red. Which is a good sign that you might not want to engage. On the other hand, if you out-level an enemy by 10 levels or more, their color will be green. Which is a sign you should be able to handle the fight easily.
If you don’t know how to mod Skyrim, check out my beginner’s guide to modding Skyrim SE (Special Edition). It opens in new tab so go ahead and click it.
It’s the same for LE (Legendary Edition). You just need to download appropriate mods between them.
Once you’re ready, download & install Display Enemy Level from Nexus. This link is for Skyrim SE (Special Edition).