need help with post display on homepage

That’s not quite the behaviour I’m seeing. At the time of writing you have a full post displayed on your site’s main page and if you click that it takes you to the full post in the category ‘Dereck’s blog’ not an excerpt?

Anyway, to get an automatic excerpt (first 55 words) of posts on your main homepage, you can use the Template Tag the_excerpt() in your index.php file instead of the_content(). Then when you click the post title, WordPress will take you to the full post. The Category pages on your site (the links under the title ‘Athlete Blogs’) are currently displaying excerpts of posts in this way.

Yes.
You can use the more tage <!--more-->. You can put this in the post where you want the text to stop for the excerpt. Or you can write a custom summary in the excerpt field when composing the post.

I tried that but for some reason it didn’t work on the homepage

You could use that quicktag to manually designate a “cut-off” point for the post to be excerpted on a post-by-post basis, however, that might not be the best option if the site has posts written by different authors.

The more tag shows up in the text

hmmm….
You might read the codex on excerpts.
https://codex.www.ads-software.com/Customizing_the_Read_More

(dumbass award to me) I was typing the HTML code in the visual editor

In my original post I linked to info in the Codex on how to use the_excerpt tag, if you want to use the more quicktag instead then checkout this page of the Codex https://codex.www.ads-software.com/Customizing_the_Read_More

You will see that you can have linked ‘teaser’ text such as ‘Read More’ at the point in the post where you add the quicktag, or you can hide the teaser text from appearing in your post.

[Edit: Apologies, seems I took too long to type my reply :-)]

So is it working?

yes ??

Thanks