I'm a little confused about how to keep track of my purchases in my accounting program. For example, I go to the ATM and take out $100, and then I go to a store and spend $50 of it on groceries. In my program I want to keep track of the cash withdrawal, but I also want to keep track of the $50 in the grocery category. How can I enter both without creating a double entry?

You can do it in several ways, it depends on how much detail you want to keep.

What I do is having a Cash account.
When I withdraw from the ATM, I enter a transfer from my bank account to the cash account. And when I buy something in cash, I enter an expense transaction in the cash account.

You could enter an expense transaction directly to the bank account, but then it will be harder to reconcile, because the amounts won't match your bank statement.

Awesome! Thank you!

I do it slightly differently: I have a category "Cash Withdrawals." Then I use splits to specify individual cash expenses. Since I don't keep track of all cash expenses, usually, some cash remains unallocated, but that's OK (remains as Cash Withdrawal). This way, all cash expenses stay within the account the cash was drawn from.

I'll read about a split tomorrow. Thank you!

Splits are useful, e.g. with department stores, where you buy good from different categories. You can have a single entry for the purchase and still enter the details.
Splits are also useful for income categories. You can split your gross paycheck in salary, income tax (federal/state), 401K contribution, health insurance, etc.

I just started in on the manual. It's a lot to read, but it sounds worth it. Thanks for the help everyone. I really like this program. I don't really need a degree to use it!