Coins is going to equal a new IntValue object we're creating.
An IntValue object is an object that holds a number (so, similar to a variable, but other parts of the game can read them easier.) You have to create the IntValue object by telling Roblox to create a new instance of the IntValue.
Set the player as the leaderstat's parent (remember, parents hold things, so if the player is the parent of the leaderstats, then the player is holding the leaderstats model.)
Set the leaderstats as the coin's parent (remember, parents hold things, so if the leaderstats is the parent of the coin, then the leaderstats are holding the coin.)
How many coins do you want your player to start with at the beginning of the game?
(It'd probably be impossible for the player to start with less coins than the cost of their first lemonade stand, so the example starts with 100 coins.)