What is the string for currency? Like, in the Attributes tab, what is the string for the MONEY? After you put the name of the money type (currency), that is when the string comes up. Or is it just the value of how much money you want when the game starts? If so, then how do I decrease the money when I buy things?

currency (like many things) should be done as~via attributes instead of trying to use actual objects for what you want to do.

you don't want to have actual~physical "gold_coin" objects as your currency, moving back and forth, instead you want to have a "virtual" currency, which is done by the attributes, which you then can adjust easily for your (again "virtual") transactions.

first, you need to have a "cash" amount:

Object -> Attributes (Tab) -> Add Attribute:

Object: player
Name: cash
Type: int (integer) or double // NOT as a String Type!
Value: 0 or 0.00 // or whatever you want for your starting amount

then your item objects need to have a "price" amount:

Object: wooden_sword
Name: price
Type: int or double
Value: 10 or 9.99 // or whatever you want for your item's price

now for the operator (addition, subtraction, multiplication, and division) expressions for attributes:

Add a script -> Variables -> Set a variable or attribute ->

(hopefully you can figure out how to set it up correctly in the GUI~Editor)

in code, it looks like this, for example:

player.cash = player.cash + 10
player.cash = player.cash - 10
player.cash = player.cash * 10
player.cash = player.cash / 10

How it works conceptually:

player.cash (intial amount) = 100
player.cash (new amount) = player.cash (old amount) + 10

player.cash = 100

player.cash = player.cash + 10
player.cash = 100 + 10
player.cash = 110

player.cash = player.cash - 10
player.cash = 100 - 10
player.cash = 90

player.cash = player.cash * 10
player.cash = 100 * 10
player.cash = 1,000

player.cash = player.cash / 10
player.cash = 100 / 10
player.cash = 10

and now for your "buy" verb:

wooden_sword -> Verb (Tab) -> Add a verb ->

(hopefully you can set it up in the GUI~Editor)

in code, it looks like this:

<object name="wooden_sword">
  <inherited name="editor_object" />
  <verb name="buy"><![CDATA[
    if (player.cash >= wooden_sword.price) {
      wooden_sword.parent = player
      player.cash = player.cash - wooden_sword.price
    } else {
      msg ("You can't afford that item!")
    }
  ]]></verb>
</object>

this isn't the best way to do this stuff, but it's the simpliest. If you want a better way, it'll get a bit more complicated, such as with using Object Types and etc.

----------

The Attribute Types:

your most basic type is the String, which is just a bunch of characters (letters, numbers, underscores, and etc):

Examples of Strings:

dead
wooden_sword
dungeon_level_5
alk329dndnljasdf3993893
a
3

when we apply an equal expression with a number to a String, we have our Integer (int) Attribute Type:

String: cash
Integer: cash=0

when we apply an equal expression with a decimal number to a String, we have our Double Attribute Type:

String: cash
Double: cash=0.0

when we apply an equal expression with a "true" string or "false" string to a String, we have our Boolean Attribute Type:

String: dead
Boolean: dead=false

while not the Boolean Attribute Type, there's many other forms of booleans (string=string) too:

(booleans are maybe better understood as "flags")

String: tv_power
"boolean": tv_power=off

String: answer
"boolean": answer=no

String: answer
"boolean": answer=1

String: race
"boolean": race=human

A Script Type Attribute is one (a Script) or more (a Script Block) expression lines:

if (orc.hp=0) {
  player.cash = player.cash + orc.cash
  player.experience = player.experience + orc.experience
  foreach (item_x,orc.item_list) {
    item_x.parent=player
  }
  orc.dead=true
}