How to find correct schema definitions for my website

I have various articles on my website basically circling about psychology and psychotherapy. On a few articles in which I have added schema.org definitions, here is some examples of the itemprop and itemtypes I’ve used:

<div itemscope itemtype="https://schema.org/MedicalWebPage">
<link itemprop="about" href="https://schema.org/..." />
<link itemprop="specialty" href="https://schema.org/..." />
<meta itemprop="name" content=".. " />
<meta itemprop="alternateName" content=".." />
<meta itemprop="keywords" content=".."/>
<meta itemprop="aspect" content=".."/>
<div itemscope itemtype="https://schema.org/Article">
<meta itemprop="dateCreated" content=".."/>
<meta itemprop="datePublished" content=".."/>
<meta itemprop="dateModified" content=".."/>
<meta itemprop="headline" content=".."/>
<meta itemprop="image" content=".."/>
<meta itemprop="discussionUrl" content=".."/>
<meta itemprop="url" content=".."/>
<span itemprop="author" itemscope itemtype=".."/></span>

I have gotten to a stage where I’m totally confused. I don’t even know if it makes any sense to have so many markup definitions for an article page (like “url” which only contains the article’s URL, or ‘keywords’ which are contained in the header anyway). I haven’t seen Google displaying any of those properties anyway.

On top of that, I am not sure how to find the correct values for the property values, like:

• https://schema.org/MedicalTherapy
• https://schema.org/Psychiatric

Question(s):
Is there any “official” table of item types I can use to find out which properties fit best for my respective articles and papers? Most I’ve found are for medical use, but not well applicable for psychology.

Note: I am offering article ratings. On top of that, I wanted to use some schema markup to help search engines “understand” the topic of my articles better. So to explain that the respective page is, for instance, about psychology, the issue of anxiety, and treatment methods, and to markup several sections of my articles (‘definition’, ‘treatment’, ‘classifications’, ‘caveats’,…) would be nice.