Summarize:

It can be hard working up the nerve to talk to your crush. Try sending them a text or an instant message instead. Keep the first message brief and light -- send them a funny picture or link, or think of a question they would know the answer to. If they continue the conversation, you can gradually write longer messages. Don't reference things that you have no obvious reason for knowing about them. For instance, you wouldn't want to start the conversation by sending them a picture of an adorable koala if they've never actually told you they like koalas. However, if they have bright red hair, you could send them a silly article like "Why People with Red Hair Are Smarter Than Anyone Else." Always wait for a response before sending another message. It's easy to freeze when you finally get the opportunity to talk to your crush, so you might want to think about what you'll say beforehand. Be careful not to plan things out too much, though -- you might end up sounding like you're reciting something you've rehearsed, and you could get thrown off if the conversation doesn't go exactly how you imagined it. After all, it's entirely possible that your crush likes you back, in which case they may be just as nervous about the conversation as you are. Instead of focusing on whether or not you'll be able to make a good impression, just remember that they might be trying to get up the nerve to talk to you too. It can be intimidating to start a conversation with your crush, but there's no better way to find out if they're a good match for you. Just think of it like any other conversation: you can start by talking about a neutral subject that you have in common, like homework, the weather, or a local sports team. If that goes well, ask them a question or two about themselves to keep the conversation going. If it seems like the conversation is going well and you want to keep your crush talking, ask them questions. It helps to ask a simple question and then follow that with some related questions. For instance, if you ask your crush what their favorite movie is and they say The Avengers, you can ask if they've seen the latest Marvel movie or what their favorite character is.
Start with a text conversation if you're too shy to speak up in person. Have a rough idea of what you're going to say ahead of time. Keep in mind they may be nervous too. Start a conversation about something you have in common. Ask questions to keep the conversation going.