Well, for that purpose I can only advice you to eat before- but something light, light fruits, vegs... Remember that you can't drink too much water after without eating too, for when you sweat, you lose minerals and salt too, and drinking just water will make the percentage of these too minor.
Also, make sure to not stick to the aircon afterwards, you are likely to get sick heh.
And put some sunscreen! You don't wanna get burnt
Have fun, and good luck! Of course you can!
My boyfriend and I plan to have a couple of days walk of a Marathon. More for the fun than for the exercise, but it can't really harm =]
