French advance variation
An isolated pawn isn't a weakness if it leads to more activity, better placed pieces etc. It can be a strength. I'm totally happy to play either with or against isolated pawns, depending on the position.
Changing the subject back to the French Advance variation, it's perfectly ok for white on move four not to play c3 but to take on c5 instead. I think white can maintain a slight, tactical edge there, whereas in the main c3 lines, black seems to equalise, even where white stodges it up completely by playing a3 too.
The position may be arrived at by 1 e4 e6 2d4 c6 3 Nf3 d5 4 e5 c5 5c3 a6 6Bd3 7 cxd4 Nc6 8 Nc3 Nge7 After white castles...black can play Ng6 or Nf5. One site call masterchessopen.com calls it the French advanced Paulsen Najdorf which means it bears resemblance to the Sicilian Najdorf. The move c6 to c5 is played due to the fact that black can also transpose to the stonewall defense depending on what white plays.>>
Tommy, that's a Caro Kann where black played the poor move, e6. It's poor because it blocks the c8 bishop. It should be better for white due to the pointless waste of a move. I doubt white should play 5c3 in such a position. Probably just dxc keeps the game open, favouring white.
<<There is the closed variation with 6.a3 c4! Black can count on an advantage>>
Not at all. It's a slight plus to white.
I took a look. The one game I found that was relevant, the white player went badly wrong round about move 4 by playing the pointless Bg5. I'm afraid you'll have to get your mentor to play against some decent players. Say 1800 +?