What symbols do you use when writing text messages sent by the protagonist in a novel?

Double quotes.

Using double quotation marks is generally used to clearly distinguish the speaker, and it is necessary to allow readers to quickly distinguish the subject.

For example, if Xiao Ming sends a message to Xiao Hong: "Have you eaten yet?" Will it be awkward to read the text like this?

It is also possible to use this symbol in many articles, most of them do.

On the issue of commas and colons, use commas in a sentence and colons in direct quotations. Words such as shouting and shouting are followed by colons. If there are only words in a sentence, then Colons cannot be used. This is a basic punctuation application.