Platon Fields & Subtheming

Any suggestions/guidance? Objective: After creating content/types and activities/types, I need fields to render in-line and for the field labels to be formatted, e.g. Label : then value. Problem 1: The form for configuration presents great, but then the fields render as an unformatted list/blob on pages/content/activities, etc. The inline formatting option doesn't work ( and unfortunately there doesn’t appear to be any basic field formatting for content “out of the box” for the theme, therefore it’s a dev effort to address this which lead to: Problem 2: Struggling to create D8 sub-theme ( Drupal steps don't seem to work, and haven't found other steps that work. I know people do this, so hoping someone could share – reinventing the wheel is costly. Apologies in advance if repeating/misstating the issues. Thanks.