All 3, hearthfire, dragonborn, and dawnguard, and there is so much new stuff. What should I do first?

Ah congrats! It's really up to you , whatever you feel like doing first will be fine. I would advise to wait on Dragonborn until you get a little higher in lever, level 30 would be good. The enemies on Solstheim are very unforgiving. If you fell like taking a break from adventuring, then build a house. So so so much you can do. Have fun!

IMO Dawnguard makes sense anytime you feel as though your character should help the dawnguard/vampires, Dragonborn makes more sense after the entire MQ. Overall, it does not matter when you do anything though.

You can start working on your house as soon as you get the letter. Level 8, I think? Then at level 10, you can start Dawnguard. By the time you finish that, you should be strong enough to start Dragonborn.

Whatever you do, save the best for last (Dragonborn).

You can do either Dawnguard or Hearthfire first. Of course, it all depends on your character.

It's all up to you.

Hearthfire isn't a questline, so it's not something you'd do before or after, is it? It's something that can be played on and off between all questlines.

I know hearthfire is about building and adoption, etc. and that dawnguard is about the return of a vampire lord, though I do not know much about dragonborn, only that some dragon priest named miraak is in it, can someone fill me in please? And how do I start the quest?

You sure you want spoilers? To start it, go to windhelm docks and ask the captain of a ship there to bring you to solstheim, an island off the cost of Morrowind and the setting of the Morrowind DLC Bloodmoon as well as Dragonborn.

I know all about solstheim, I have been there enough times, and did I say I want spoilers? I was asking how to start the quest that involves miraak.

Started or completed "The Horn of Jurgen Windcaller" quest and you will eventually meet 2 cultists in one of the major city that will start it. Also, you did ask "can someone fill me in please" which seemed to refer to the previous line about not knowing anything about it except Miraak.

Thank you. And I said fill me in please as in " miraak the first dragonborn returns and plans to......." that is what I meant.

Ever since i got Hearthfire i make an effort to hold off on buying a house until i get the letter from the Jarl of Falkreath. I used to buy Breezehome, but now i dont even do that, once i get the letter and around 8-9k gold i buy Lakeview. The cool thing about the steads are you can build a garden for alchemy ingredients, greenhouse for even more ingredients, kitchen, alchemy lab, enchanting table, all related smithing stations. There's extra fluff you can get too but you'll figure those out as you go along.

couple of tips that may help you with Lakeview

-if you plan on building the main hall or wings, after you buy the stead you should buy at least 140-200 extra lumber from the mill

-save before you start building

-bring at a minimum 10-16 iron ingots (not iron ore) and build a smelter on the stead right away

-bring an extra 1-2 corundum ingots or 2-4 corondum ore for the main hall (need it for the main hall door lock)

-bring another 8-12 corumdum ingots or 16-24 corundum ore for the 3 wings and 2 chests

-bring 60-100 iron ore OR ingots to be able to construct the main hall and wings and a few furnishings

-if you want more furnishings double the iron amount above, wiki sites can provide you with exact quantities for full furnishing

-main hall construction table has materials list for alchemy lab and enchanting table

*note* the stead has a chest outside with a few ingots, but it will only be enough to build the small house, there wont be enough ingots build a smelter or the main hall.

Does the installation of Dragonborn automatically trigger the quest, or is there something you need to do before starting it? I'm worried that once I install it, my new characters won't be able to gain something they need when killing dragons, and will be forced to do the Solstheim quests just to get things back to normal in the vanilla game.

You need to be Dragonborn before the DB Main Quest activates. If you want, you can install it, and just put it on hold until you're ready.

Ah, thanks. That's the exact spot where I put the MQ on hold, so I should be able to activate the DB quests. It does mean that you probably can't learn a certain fun sprinting shout on a new character without triggering the DB activities.. or maybe you can learn the shouts and leg it from the place before the final speech...