Early on in Empyrean, most enemies will be a struggle. Try to pick your fights carefully, and explore. Exploration will net you the most amount of experience early on, so discovering all of Whiterun Hold should bring you close to level 5-10, where you can start picking fights with bandits in the mines and such. Take your time, and try not to get surrounded. Make use of any ranged options you may have, or smaller weapons, as Precision will impact swinging larger weapons in tight quarters, for both you and the enemy. Bleak Falls Barrow can be completed as early as level 10, with decent follower support, but for a lone wolf style playthrough, I would suggest level 15-20 unless you like a challenge.
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Ensure you are making full use of the Campfire skill trees, as they provide more tools to enhance you're early game play. Sitting and resting (which can be accomplished either on a bedroll, or by pressing B) will improve your wayfaring skills, eventually unlocking the compass toggle, allowing you to see where enemies are coming from, as well as orient yourself without opening your map every 5 seconds.