All of the fonts on Typekit support the English language. You can browse fonts that support both English and other languages by selecting them from the list of supported languages in the sidebar under browse fonts.
English is included in the default option, so the English characters will be available to your website within a few minutes of publishing your kit.
You may also create a custom language subset which includes English, to reduce the size of your kit. The Language Support & Subsetting help page has more information on the character set options.
All fonts on Typekit include the following letter characters, at minimum: