Read More Button Display

Hello,

I'll dot-point this, to keep this brief as possible.
> Have tried to find an existing answer on the forum, but no luck so far.
> I'm trying to post some articles. Current access to full article is by clicking the feature image for each article.
> I Cannot currently get a snippet of the article and a "Read More" button to display under feature image - it looks more professional if I can - I have tweaked things, in the "appearance/customize" section, but no luck.
> I'd like to please, if possible, 1) have a snippet of the article [under the feature image] 2) a Read More Button below the snippet and 3) The link to original article source [currently appearing under the feature image] to appear at the end of the Full Article [ie, AFTER clicking the Feature Image or "Read More" Button.

Any help appreciated please.

Thank you.