Guest access applies to any visitor to your Moodle site. If you have the guest enrolment plugin enabled in a course, and you've allowed auto-login guests at site level, then your course will behave the way you have described - anyone can go and have a look, read the content and decide if they want to enrol properly (you'll need self enrolment, or PayPal enrolment, or something else to allow them to do that of course).
Guests cannot reply to forum posts, submit quizzes, assignments or do anything other than read though! If you want them to experience the course properly, you'll need to create a demo student account and publish details in the course or elsewhere on the site.
Because they are not enrolled, the course cannot appear in the My Courses block, and as Helen said earlier, guests don't even see that block!
So, on the basis that guests can already get in, Derek is right - just publicise the course on your front page. You already have at least 4 marketing spots on your front page with that theme.
ps. Even though you allow language switching on your site, it's only changing the Moodle language, not the stuff you have typed. The Moodle language packs don't translate your text, just the text generated by Moodle. You might want to have a look at the multi-language filter: https://docs.moodle.org/en/Multi-language_content_filter