Just accept that they are part of the language of business and as you begin to use them the mystery will evaporate. So, I'll gratefully accept my chance to further confuse the issue and continue on. For each entry you must enter at least one debit and one credit, and the total of the amounts on the right must equal the total on the left. Really, it's just that simple. You are increasing your expenses by the same amount - and there you have your two entries.
Cash gets the negative entry, or credit and small tools gets the positive entry, or debit.
OK, I just lost you - but it's easier than it you think. An asset is a positive number in the system. To the computer, however, liabilities are actually negative numbers - because they need to be subtracted from the assets to come up with the total value of the company. It's not something you have, it's something you owe. So stay with me - if you credit a liability account, you are actually adding a negative number to a negative number.