Posting to the correct forum would help for a start ;-) You posted to the Expression Design
forum, not Expression Web
There was an old "marquee" tag but I don't believe that's part of the current HTML5 standard.
The basic way, something like this:
<marquee>This is basic example of marquee</marquee>
Most users would probably find it annoying and it probably doesn't meet accessibility standards for the web. Refer https://www.w3docs.com/learn-html/html-marquee-tag.html.
There might be more modern methods, but nothing built into Expression Web (if that was your question...).
Andrew M
http://www.murraywebs.com
"Nothing spoils numbers faster than arithmetic!"
-- Peppermint Patty (Peanuts, Charles M. Schulz)