The aim in chess at the beginning is the deploy all of your pieces to their most effective starting positions. For example, your knights of f3 and c3 and your middle pawns covering the center, etc. Unless he/she blunders horribly in the opening, you should not worry about attacking your opponent until all of your pieces are developed. Only then should you worry about tactical manuevers that can force your opponent into weak positions that you can then exploit until he cannot defend against a checkmate.
Aim in chess ?

Well the ultimate goal is always checkmate. However you shouldn't expect to be checkmating right at the beginning of the game unless serious blunders were made, so instead you work towards that goal by trying to employ your forces as effectively as possible.
Here is a list of some opening don'ts
1. Don't make unnecessary pawn moves.
2. Don't bring out the queen too early.
3. Don't move a piece twice in the opening.
4. Don't trade a developed piece for an undeveloped piece
5. Don't exchange without good reason.
6. Don't develop just to bring a piece out and not with a specific purpose.
7. Don't block your center pawns.
8. Don't impede the development of other friendly pieces.
9. Don't weaken your king's position or move your uncastled king.
10. Don't move knights to the edge of the board.
11. Don't waste time or moves.
12. Don't indulge in pawn-grabbing.
13. Don't sacrifice without good reason.
14. Don't refused a sacrifice because your opponent made it quickly and confidently. Analyze then decide.
15. Don't play without a plan
16. Don't develop in an uncoordinated way
17. Don't change plans from move to move.
18. Don't remain uncastled for too long.
19. Don't advance pawns too far too soon.
20. Don't ignore your opponents moves
21. Don't give pointless checks
22. Don't capriciously avoid making natural captures and recaptures
23. Don't take your opponent too lightly or too seriously.
24. Don't play a set order of moves without regard to your opponent's responses.
25. Don't open the center with your king still uncastled.
Of course this is just general guidelines, obviously there are times to break them but you should usually do them only with good reason. For example if your opponent hangs pawns on mistake you can grab them, or maybe taking an undeveloped piece with a developed piece wins you a pawn and then its a good idea...but a good guideline.
Hi,
I am new in chess and just want to know that what should be the aim in chess at the begning of game .. ? To drop or to capture the oponnent pieces ? Making the defence by castling ? Try to ckeckmate ?