I understand that if you become a vampire BEFORE you start the dawnguard quest line, you can still become a vampire lord. (Obviously I will be

joining the vampire clan as you can tell from my statement above)

But I looked ALL over the internet I can't find any information, not CONCRETE DETAILED enough to tell me is this a good idea or not. Will it ruin my game? bugs? story? is it better to just stick it out until I get to the story part to TURN into a vampire lord?

Any information will be helpful thank you.

It's up to you. It won't bug your game. Harkon will recognize that you're already a vampire, but he thinks it's a watered down strain and he'll offer you "true" vampirism.

Has no effect. Serana has different dialogue but isran doesnt notice (if you chose dawnguard) until later. Im not sure if you lose harkons gift and become a regular how others in court treat you. I assume its same as human.

ah ok thanks

Its the same if you're already a wearwolf. Harkon will mention he can smell it on you, then remove it should you choose to join the Volkihar.

i always become vampire first before joining the volkihar and i always play as a vampire it really helps my character to actually fit in the story of vampires and not like you got cool powers bro... make me one of you.