First of all, it is necessary to delimit your ground to be sure that your swimming pool can be inside.
Then you have to choose your pool and size. You can do this for inspiration with the models proposed by archiplain:
Rectangular pool:
Square pool:
Round pool:
And why not a spa:
You can add:
Parasol, striped of blue:
Square parasol:
And others.
And to rest, you can install:
Deckchair 1:
Deckchair 2:
And others
You can change the dimensions of each object, and even the pool.
How to find these objects to make your pool? In the Archiplain house plan editor, just click on Exteriors / pool
More: