So far, I have been setting off plays/ def plays etc and then clicking save after setting all 6 tabs - naming it after the team im playing

Next game I make a few tweaks etc then re-save again as something new.

For now, I'm not interested in being able to use saved plans etc, and I've just realised that I think whatever adjustments I make it automatically saves them for the next game and that I dont need to click save for them to work in the next game - right???

You only need to save the game plan if you wish to load it in another league or snapshot it so you can come back to it after you have experimented with it. When you save it is just storing a snapshot of the current state; what you see on the screen at any given time is the current game plan you would use in the next game.

Great so basically auto save like on most games! You've thought of everything!