Caro-Kann Defense: What to do if Opponent Plays Pawn to C4? Do I continue with Pawn to D5?


indeed. I guess, you should provide more context if you want a reasonable reply. Which line or variation of the CK are you talking about?
It's sounding like the OP is asking about the Pseudo-Panov (1.e4 c6 2.c4). If that's the case, then 2...d5 is one of the best responses.

Oh i did not know it's called the Panov version.. Thank you. Is there any videos covering the Panov? So far i've only seen videos covering the advanced, exchange, tartokower, classical.. this is my first or second time where someone plays Pawn to c4 and i feel stuck. I would be up if there's an exchange as my queen will take the pawn?

Chess.com has a very good overview lesson on various sidelines of the Caro-Kann by GM Sam Shankhland. I also recommend the book The Caro- Kann by GM Lars Schandorff. Panov is one of the most important lines in CK.

https://youtu.be/alLPVK4wCiA?si=r92549e_-Uh0ehnn

Hi!
If you would like to stay in Caro -Kann territory then 2...d5 is the way to go. This leads- as some other said -to the Accelerated Panov Attack, which has some subtleties- compared to the Panov proper -that Black needs to know.
On the other hand, you could play 2...e5 and the game takes a totally different shape towards an Old Indian defense, after for instance 3. Nf3, d6 4. d4, Nd7
Good luck!