Build options for creating an iOS version of app developed on Windows system?

BASIC QUESTION: What is the best way to go from a Unity script that works when built using a Windows platform selection and to a Unity script that will work on a Mac using the Unity Webplayer on that Mac?? BACKGROUND: Using the "Universal Windows Platform" Build option I have created a simple working Unity test app that I created on a modern Windows 10 system. Using the "PC, Mac & Linux Standalone" option I have done a "Master" Build of it and successfully run the resulting .exe on a separate Windows laptop using Unity WebPlayer.

I now want to do a Build that generates an iOS version of the app that will run on a Mac Mini. FIRST ATTEMPT: Since "Mac" was included in the description of the option I chose for the "Master" before, I used the "PC, Mac & Linux Standalone" option's output (A data file and a .exe file) unchanged on my Mac Mini. That failed. The Mac Mini warned that it had no Windows capability. SECOND ATTEMPT: I then tried to do a Build using the "iOS" Platform option. I immediately ran into my first roadblock on this try. To get past that, I had to download and install the "Unity iOS Support" package (The download file to do this was "UnitySetup-IOS-Support-for-Editor-2017.2p2.exe"). This step got me past the initial roadblock and I was presented with Build options "Release" and"Debug". Neither Build type would complete and error messages warned of missing files that my C# scripts require. It gets pretty arcane at this point because the missing files are associated with some voice recognition software that came with some scripting examples I found on the web that fit my needs. I think they are found in the reference to one of the statements I got from the scripting example, i.e. "using UnityEngine.Windows.Speech;" HELP APPRECIATED: I'm pretty new to Unity but had been getting by fairly well until I ran into this multi-platform problem. Unfortunately, I need to solve it to complete my project. I've received some great help from the community so far, all of which is greatly appreciated.
Cheers, Bob G.