So many different bidding situations to remember and even the most experienced partnerships will sometimes find themselves in uncharted auction territory. Any work you and your partner do away from the table and in preparation will be helpful.
 
Do you know what this bidding sequence shows?
1♥    P     2♣   P
4♣
 
It's a pretty simple auction, just the first three bids with no interference from the opposition but I suspect there will be quite a few different views on the meaning of that 4C bid. Some players will automatically assume 4C is Gerber, asking for aces. Some players will think that the 4C bid shows club support and it's a jump so it's strong, I guess, but exactly how strong?
 
In any partnership I play in that 4C bid would show 4-card club support and a strong hand. Stronger than 5C. Forcing to game. It's an auction that I'm familiar with and I've had the discussion.
 
While we're at it, let's simplify the auction. 
1♥    P   2♣

 
An opening bid and a change of suit at the 2 level. What could be simpler? That 2C bid shows 10+ points for most players and I like to have the agreement that it's forcing to 2NT. Now the auction continues:
1♥    P   2♣   P

2♦
 
Can that 2D bid be passed? Not for me, because of that agreement; after a 2-level response the bidding can't stop before 2NT. You and your partner might think differently but I sure hope you have an agreement because it's a pretty simple auction! If you have agreements about some weird convention that you love to play but you haven't discussed whether 1H 2C 2D is forcing then it's time to have that discussion.
 
Luckily, many players love talking about bidding. For a lot of players, having a bidding system discussion is a fun, interesting thing to do. Useful, too, because it's work you can do away from the table that'll enable you to reap the rewards when you play.
 
Unluckily for me, I find system discussions useful but painfully boring. But I know that if I do the bidding preparation then, heck, there just aren't that many contracts that you can end up in and bidding becomes kind of easy.
 
Card play is something else. 

West leads the Ace, King and Queen of spades against your rather adventurous 4H contract and you ruff the third spade in your hand.
 
You've lost two spades and still have the heart Ace to lose. Somehow you need to avoid losing a second heart trick. Can you see how to do that?
 
You need to hope that one player has the doubleton Ace of hearts. Suppose West has Ax. You play a low heart towards the Q in the North hand. West plays low and your Queen wins. Now you play a low heart from both hands. West has to play the Ace now and you've still got the King to draw East's last trump.
 
But wait! - West passed on the first round and then led the three top spades. West would have opened the bidding with the Ace, King, Queen of spades and the Ace of hearts. East must have the Ace of hearts. It'll need to be East with the doubleton Ace to make the contract.
 
Here's the full hand:

After ruffing the third spade in your hand play a club to the King and a low heart towards the King of hearts in your hand. East plays low and your King wins. Now play a low heart from both hands on which East plays the Ace. You've still got the Queen left to draw the last trump.
 
Phew! But how do you do that stuff at the table and how do you do it quickly enough that you can finish the hand in time?
 
Playing the cards is hard work and you're going to have to think.
 
On Saturday and Sunday I played bridge. I'm not 20 years old anymore and two days of bridge wears me out. It's Monday morning, my back is sore and I'm tired.
 
When I play bridge I know I'm going to have to work hard on every hand. Even then I'll make lots of mistakes. Perhaps you know the simple secret to good card play. I don't. Thinking makes my brain stronger so I just keep trying.