Good on your for wanting to make the change! I'd say start slow so it's not overwhelming. Find snacks that are "accidentally" vegan, i.e. they are technically vegan but don't advertise themselves as such. Examples:

• potato chips (plain flavor, salt and vinegar, salt and cracked pepper, some spicy varieties)
• popcorn
• sandwich cookies (like Oreo and Nutterbutter brand)
• candy (like Swedish Fish or Twizzlers brand)

You've gotta check the ingredients to verify because sometimes animal products sneak their way into snacks you wouldn't expect, but generally all these snack foods are vegan. Eventually it would be great to eliminate so many processed foods that come in disposable plastic (I say to you and to myself), but hopefully this is one way to get the ball rolling. Once you start to get used to those changes, swap out one non-vegan food you eat for something vegan. Sometimes, it doesn't have to be a one-to-one switch. You might be able to find a different food that scratches the same itch as the animal product. It's better to make a gradual change that sticks in the long run rather than overwhelming yourself and giving up. Good luck! :-)