2D games where you create units that automatically advance to the enemy base? (Help)

Right now we’re making an educational 2D game, strictly no killing, that is closely related to Cat War. Link below is related to what I’m talking about
https://gaming.stackexchange.com/questions/51504/genre-name-for-real-time-2d-games-where-you-create-soldiers-that-automatically

The problem is we don’t fully grasp the basics of Unity and we only base on videos and certain assets that is related to what we make.

What we need is a guide in making its basic structure.

Thanks.