can anyone tell why c4 move for black is a mistake here?

With every pawn move you must weigh what you gain against what you give up. 

What does black gain with the playing ...c4?

What does black give up playing ...c4?

E4 is white's next.  If you play c5, black has no good answer to that, dxe is terrible and if you don't exchange e5 is going to be an issue as the black bishop is misplaced on d7, and the black knight will have to make an inferior retreat if e5 is achieved.  By contrast, if you play rc8, be7 or bd6 and white plays e4, you can exchange in the center and give white an isolated dpawn.  

With castling short and this pawn structure, c4 would generally only be played if white had a bishop on d3, and not necessarily even then.  

Black's bishop to d7 was a big mistake as well.  It does nothing there, and even if it goes there eventually for lack of better options, there is no benefit to developing it so soon.  

c5 can be strongly met with e4! dxe4 ng5 and you have two pawns hanging. You always have to watch out for those pawn breaks. If you don't capture and let that pawn steamroll to e5, it's pretty much f***ed. 

Just normal developing move like Be7 and 0-0 and that's fine. 

This blocks the way for the next pawn 

in my opinion, this move is too committal. white simply plays Rb1 followed by b3 and his rook has control of open b file, when black has not yet completed his development. black should play Be7 followed by 0-0.

k