I love thinking about grammar. I love helping people understand it. Here are two tips for you.
The colon replaces words like “such as” or “includes.” You don’t need both. So you’d write this: I enjoy many pies such as pumpkin, cherry, and pecan. Or you’d try this: I enjoy many pies: pumpkin, cherry, pecan.
The semicolon connects two complete sentences that relate to each other. To remember this, ask yourself if you could use the word “because” instead of the semicolon. Like this: We traveled by car instead for Thanksgiving; the prices of flights increased significantly.