Well you have enough space for all of the above if needed.
I will say that when i have done my garden I wish i put pipework under ground to automate the watering of the garden instead of just having a hose pipe, this last year with the heat wave half my plants have died out due to how little chance i had to water and an automatic soultion would have been best before to put in before i put a patio/shed down.
Try and put a plan in place on how you want it to look at the end, its a lot harder to go back and sort things out later.