Can't find long term plan for Black I am working on multiple lines from Scandinavian defense, with the goal to resurrect them. 
One line I'm working on is 3...Qd8, and I have managed to achieve quite playable positions ( the results are the best so far, regarding other lines like 3...Qe5+ or 3...Qa5/Qd6 ). 

Although I can get rock solid position from the opening, I just can't find the long term plan for Black. 

The line I am referring is :

[Title "Scandinavian defense, with Qd8"]
[fen ""]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd8 4.Nf3 c6 5.d4 Bf5!? 6.Bd3!? Bxd3 7.Qxd3 e6 8.O-O Nf6 9.Bf4 Nbd7


Here is a diagram that illustrates the kind of positions I usually face:

[Title "Black to move"]
[StartFlipped "0"]
[fen "r2q1rk1/pp1nbppp/2p1pn2/8/2PP1B2/2NQ1N2/PP3PPP/R4RK1 b - - 0 1"]


I just don't know how to battle White's space advantage. I don't have a plan for engineering a freeing break.

Is there anyone who plays similar pawn structure, and is willing to give me some pointers on how to play this position as Black?
For logical reasons the 3...Qd8 Scandinavian is not popular among top grandmasters whatsoever , Stockfish 5 gives it 0.45 after running for around a  5 minutes compared to 0.00 in the French Defense after 3.Nc3 Nf6

For this variation I would recommend looking at the games of Montenegrin Grandmaster Nikola Djukic, who is the only grandmaster who employs the 3...Qd8 variation regurlarly. He also has a plus score with it against an opposition elo average of 2496 which is nice. 

The 3...Qd6 Scandinavian is a lot more popular. The very strong Grandmaster Sergei Tiviakov has implemented it regurlarly with a massive plus score against an elo average of 2659.

The 3...Qa5 Scandinavian is the most popular of the 3, the Serbian Grandmaster Miodrag R Savic can be considered a specialist on this since he plays it approximately 71% of the time against 1.e4 with a very positive score against an elo average of 2508.

I've decided to just ignore the 3...Qe5+ variation, which is also called the "Patzer Variation" White scores 71.1% after 4.Be2

Of course this post would not be complete if I didn't answer your question on how to find a plan in the given positions.



FIRST DIAGRAM

Unfortunately the line you are referring to in the first game has only 2 games in Mega Database 2014. 

[Event "?"]
[Site "?"]
[Date "?"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "?"]
[Title "Scandinavian defense, with Qd8"]
[fen ""]

1.e4 d5 2.exd5 Qxd5 3.Nc3 Qd8 4.Nf3 c6 5.d4 Bf5!? 6.Bd3!? (6.Bc4) Bxd3 7.Qxd3 e6 8.O-O Nf6 9.Bf4 Nbd7


OK, in the final position black is solid but there is pretty much no way for him/her to win (naturally, with exceptions in human play). White is castled, has 3 pieces and a pawn putting pressure on the center with an added space advantage. White is clearly better, the game has certainly not equalized in blacks favor. Maybe you have avoided theory and complications but unfortunately that is all you have gained. 

Another problem with such a position is that black is really lacking in play here. This makes it much harder to formulate a plan of some sort, maybe this is why you are struggling to find a long term plan.



SECOND DIAGRAM

 [Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "Black to Move"]
[Black ""]
[Result "*"]
[SetUp "1"]
[FEN "r2q1rk1/pp1nbppp/2p1pn2/8/2PP1B2/2NQ1N2/PP3PPP/R4RK1 b - - 0 1"]
[PlyCount "5"]

1... Nh5 (1... Qb6 2.c5 Qd8  (2. a3 c5)) 2. Bd2 (2. Bg3 $6 Nxg3 3. hxg3
$11) 2... Nhf6 3. Rfe1 Qc7 4.Rad1


In the second diagram your main plan should probably be the elimination of the f5 Bishop, which is severely cramping your position. So therefore Nh5 comes to mind, if the Bishop retreats to g3, simply chop it off and the position is equal, however white can retreat the Bishop and it is not so clear how to proceed for black. I have given some small variations to go by but overall the position seems to be completely devoid of play for black. Black is lacking in any sort of counter-play to put it bluntly. 
OK maybe after 3...Qc7 you can centralize the rooks with rook a8 to d8 and rook f8 to e8 and slowly maneuver your pieces, waiting for white, maybe move your d7 Knight to f8 to clear open the d-file and prepare a possible ...Ng6. Black basically just has to sit and wait. The engine recommends ideas involving ...a6 but I find this quite dubious and unnatural, not suited for human play.

White on the other hand has the clear idea of d5, centralizing the rooks, h3 to maintain the powerful dark squared Bishop. The position is rich for white. Better to say the least, because he/she has a clear plan to follow by.

I know that the computer evaluation is a powerful thing, but we are not computers. I highly suggest picking another variation to go by, one which involves "play". For a position with counter-play and imbalances is much more important than a dry one such as this one despite the silicon machine saying 0.36. 

I personally think that the 3...Qd8 Scandinavian variation is a very dubious one which should be avoided at all costs by the improving chess player and should only be played for the element of surprise.

All statistics courtesy of Chessbase Mega Database 2014