Where is Dayspring cavern?
How do you solve the Sky Haven Temple puzzle?
How do I clear my bounty in Skyrim?
Most likely this glitch occurred in Riften because that is the Dawnguards area in part, so fast travel to Riften and attack a guard. Be sure that if you have a follower or Serana with you that you have them wait somewhere outside of town.
If vampire, you’ll have to become cured later to continue working with the Dawnguard. If soul trap, your stats will be partially reduced in the Soul Cairn. However, you can find your soul gem somewhere and seize it, permanently restoring your stats in the Cairn.
Overall, the physical rewards (weapons, etc) are better if you choose Dawnguard. However, you cannot regularly use the powerful Vampire Lord form until after you’ve completed the main questline, or else the Dawnguard members will not accept you.
Should I join vampires or Dawnguard?
Dayspring Canyon is the wilderness area surrounding Fort Dawnguard. The cave entrance to the canyon is located southeast of Riften, just north-northeast of Stendarr’s Beacon.