If you search you will find answers to all your questions, but I’ll give you a few tips off the bat…
You still need to use configuration.yaml for ISY and many other things. They are working toward not having to and you can get Home Assistant running without messing with config files, but there is so much more you can do when you DO use them.
Look in the development section…there is a custom component that you can install for ISY that gives you much more usability over the stock implementation. This includes climate devices installed on ISY.
Install HACS to get it installed. Just search for ISY after HACS is running.
In HASSIO you can enable SSH and samba via the addons page as well as configurator. I would say do all three without question. It will help you out a lot.
Hope this helps a bit. I know it can be confusing, but you can do quite a lot with this combo of HA and ISY. It will just take some investment of time to learn as you go.