You must be in a tropical zone - I see palm trees .What zone are you in ? How long do you plan to live in this house and are you married to the grass ? How long and wide is the garden ? Can you make a shot from the fence toward the house ( house in center ) ?

Third vote for getting a professional involved, but i'll still offer my layman's suggestion given that you're just soliciting general ideas at this point. If it was my space, I'd switch the bathroom and the laundry room around, keeping just one of the walls currently enclosing the toilet. Its hard to estimate precise measurements from the drawing, so it may not be feasible, but here's what i mean

Is it possible for you guys to put the before photos in colour so we can truly appreciate your work on this project?

My suggestion -- start with a 'base' -- do the fence in charcoal , the retaining wall almost looks brick but I'm guessing it is wood , so maybe go the same grey as that tank wall or whatever it is , and do the white pipe the same ? And then decide the purpose -- a bbq , a table and chairs , a love swing , a spa pool , a water feature , a traditional garden , a rock garden , a desert scene , an egyptian garden -- you get the idea . One or all of those , or whatever suits YOU .