Ye, I also thought about it, any advice will be helpfull.
C and D pawn tension

The main reason to attack the opponent's d pawn with your c pawn is to prevent (or try to prevent) them from establishing two central pawns, side-by-side, unchallenged -- as two pawns, next to each other, control a lot of squares.
So a few general rules to consider:
- If, by playing cxd, you can eliminate your opponent's chance at establishing two side-by-side central pawns, then you should probably capture.
- If, by playing cxd, your opponent can then recapture with another pawn, establishing two side-by-side central pawns (ideal for him)? In this case, you'll want to be poised to attack his pawns again, with another of your pawns (likely your e pawn), as you should not let him have two central pawns, side-by-side, unchallenged.
There are also tempo-related reasons to maintain the tension on the c and d pawns, related to the development of the king bishops, but those tempo issues are (in my opinion) not as important as understanding the need to prevent (or challenge) your opponent's central pawn formations.
*It's also worth noting that the above ideas should take a back seat to any immediate tactics that the position may have.*
Hello , I'm not completely beginner in the game ,but I'm still probably in the lowest tier of players . I have question about pawn preassures , especially C and D pawn . For example in queens gambit ,french defense , maybe london system and etc. often you put your C pawn ,to preassure your opponent center,or even preventing them to play in center. And the question : Is there any general rule ,when I should take enemy center pawn with my C pawn , and when I should maintain preassure between those pawns . Thank you for the answers.