Caro-Kann Advance Variation. c6 or Bf5?

I know there is a 2 year old post similar to this but I was hoping somone could help me. Recently I switched from the Sicillian (realised I wasn't that good after all haha) to the Caro Kann and I noticed most people played the advance variation. Usually I play c5 in response hoping they would take my pawn but they just play c3 to protect their pawn and the game would end in a mostly closed position which I don't play the best in. When looking at other people who respond to the advanced people often play Bf5. I've tried to play this and usually the opponent would try with Nf3 people my level (I'm a 700 in rapid btw so now you know why I don't play the sicillian anymore) play the pawn move g4 trying to kick my bishop. After this I retreat my bishop and I don't like the position. I was wondering if anyone could tell me what to play after the pawn push and what ideas I could have later on in the game?

when I mean c6 I meant c5 sorry

Take a look at Tigran Petrosian's C-K games. I think you'll find them enlightening.

Both are good. Just depends which you know better. Bf5 is the more classic move and c5 is the more modern/on-trend move.

c5 isn't very good.

Both moves are good. Just as an input: If I was Black I would be thrilled if White plays c3 after c5. Isn’t this just what CK players want? A French advance with the Bishop outside the chain? Surely the critical line is dxc5, where play can get very sharp. Bf5 has a more CK „feel“ to it, but there too, Black has to know some stuff.