Getting started with bindings and add-ons

I think I now have OpenHAB installed and working on my Raspberry Pi, but I’m confused about how to install the bindings and add-ons that I need. There is a long list of them, and I can click them to see pages of information about each one, but there doesn’t seem to be a button saying “install this now”. How do I actually install these?
What I need to do in particular is to install the OneWire binding and connect to my DS18B20 temperature sensors via a DS9490R. Eventually there will also be other OneWire sensors (e.g. humidity, atmospheric pressure, insolation). Then I need to be able to connect to my Tuya temperature and humidity sensors, and to control my Tuya radiator actuators. I’m not sure whether to do this directly using Zigbee, or to go via the Tuya WiFi to Zigbee gateway. I also need to be able to control some zone valves. I suppose I need some kind of solid state relay to control these, but I haven’t chosen the specific device yet. i also need to be able to read my oil tank level via am Apollo sensor and an RTL-SDR.

Any guidance on any of these things would be most helpful.

Thank you - Rowan

In MainUI → Settings → Bindings

The Getting Started Tutorial walks you through the process in more detail.