There’s quite a bit to consider but it’s critical to stress that websites or themes here are not the same as platforms like Wix.
It would take too long to explain the differences but there are some core considerations eg ownership, ongoing payments, technical restrictions etc. Ultimately sites like Wix serve a purpose well but no commercial website is likely to ever use it.
To use a WP theme from here all you need is your own domain and hosting with WP installed. (Most hosts have an auto install option for WP that makes it much easier and faster).
Because WP is a CMS (content management system) you can make most amends etc in then admin section of the site without any other software etc.
Most WP themes come with page builders etc to make it easy BUT to reiterate this is NOT like Wix, and is significantly more grown up.
If building a serious website was as easy as using Wix or could be done by anyone for $50 then there would be no need for web designers and developers!!
Any real estate site will be more complex irrelevant of how you build it, due to listings etc. If you want to do it properly then a WP theme is a great option BUT anyone new to this has to embrace the time and learning involved.