Thanks for checking it out! In this case, since this is a fully 3D game, there's nothing specifically isometric about it code-wise. I can just tell a unit to go from cell A to cell B and it works out. As someone who's currently working on a fully 2D tactics game, though, there's definitely some benefits to doing it all in 3D, even if you're just going to billboard most of your art into the world. Could be one option to consider.
Another option might be to not to isometric at all for now and just do a regular grid to keep things simple. If you're a beginner, you might have plenty else to worry about :)
This is also a neat video about isometric grids you might find useful: