I am new to WP (trying to help my partner), and looking for an easy to use theme that kind of looks like what I have at pritaeas.net. Basically I want the homepage to feature images (text optional) pointing to a section on the website. I have been searching but there is so much out there, I have no idea where to start or what keywords to use when searching.
Your site is pretty minimalistic, so a bare bones theme like underscore or one of the yearly releases like twentysixteen (etc) may be of use. However, they are very bare bones and need a lot of styling - even to achieve the minimalistic look. Your frontpage is a gallery / portfolio type look, so you could go for a basic theme and install a gallery / portfolio plug-in, instead of trying to find a theme with the purpose-built functionality. However, many of the better themes have a lot of modern functionality already covered.
I'm loathe to suggest a particular theme that I haven't used as the "backend" (admin) or "cutomisability" experience varies considerably.
From the commercial sites I've built, I've used colorlib themes (making child themes of them) quite a bit. I recently used a colorlib theme called dazzling for http://www.therunawayitalian.com It may not look much, but the ability to customise was an absolute dream.
The free themes are pretty good as a starting point in order to get your head around the system, but paid themes may be a good option if you need support in the early stages. Beware certain sites like https://themeforest.net/ - they have a huge collection, but they contain a large number of plagiarists, who minimally modify other themes and pass them off as their own.
For search terms, maybe minimalistic, clean, gallery / portfolio site. Good luck with it - I always poo-pooed WP until a client asked me to develop one from scratch - I was amazed at how well-put-together it is - well the 4+ version. :)
I'm really out of touch with WP, being used to building CMSes myself. Just too much info at once to get where I want to be. I have a theme installed, but am struggling to get the images on the homepage. Can't remember the name now, will look it up. Probably need to do some reading to get the basics first.
The sections needed will be for (cooking) recipes, book lists (maybe) and categorized information on animals and minerals for example.
Sounds like an interesting site!
You will probably need to create some custom post types with this variety of info. This is easily done in code for the initiated, but some nice plugins are available if you just want to get on with it. The ones I'd recommend to fulfil this are:
Custom Post Type UI: https://wordpress.org/plugins/custom-post-type-ui/
Advanced Custom Fields: https://wordpress.org/plugins/advanced-custom-fields/
You may find metaboxes useful too.
For the custom post types you may wish to set up a new taxonomy and add new categories or/and tags. This is useful if you want to have separate pages for specific post types / cats.