Text files consist ONLY of ABC's and 123's. No special, weird-looking codes exist in text files. Binary files DO contain special characters. That was a corrupted binary file. Text files just have letters of the alphabet, numbers, and basic punctuation in them.
ALL computers understand and can interpret text files.
To write web pages, you need a text editor. Windows comes with one called, Notepad. All files saved with Notepad are saved as text files. You can use a word processor like Microsoft Word to create text files, but it is a bit more complicated. Three terms you need to know are web site, web page, and home page.