There are several key concepts to understand while playing the Lego Harry Potter game.

First, there are two "parts" of the gameplay. There is the general roaming play, when you just go from room to room, getting as many coins as you can, taking your time. In this mode there is no "progress bar of coins" at the top of the screen. You are either roaming around the alley able to buy things at shops, or roaming around Hogwart's learning new spells. There is no "task" to get done to earn bricks. In the second mode, you are in a defined "level". In the level you have to get X coins (different for each level) to be awarded the gold brick and title of "True Wizard". So only worry about getting Every Single Little Coin if you are in a defined level. In general open play, there will be TONS of coins everywhere and "lack of coins" really isn't a problem :)

Next, don't obsess about coins. I know it's easy to want to get billions of coins in the beginning. Take it easy. You will be deluged with coins in this game. Just gather them as you go, and realize that it's a LONG game. By the time you reach the end you'll be swamped with coins. Enjoy the anticipation of earning those larger prizes.

Hit every single thing you can. Smash it again for good measure. You never know what will explode and give you prizes. There is never any harm in hitting everything. You can't "break something important". Try, once you get magic, zapping and blasting and levitating everything you come across.

Have fun! This game is amazing. You'll want to replay levels over and over again to figure out every last trick in them. This isn't a game to race through and "finish". It's a game to savor!

If you ever want to rewatch a fun movie, you can see them all by going "upstairs" at the tavern.

Lego Harry Potter Walkthrough