Well first of all ide start with a game of pick up sticks. But you have to do it quietly like in the grass. Depending on the size of the quiet area you could do hand stands, jumping jacks or maybe even a game of Yahtzee. But roll the dice one at a time so as to keep it quite.
Buying things in a quite area should be done very quietly like with sighn language but only use bills change makes to much noise.
Hope that helps,
When you get your grow going pop in and show us what you got.
Hay maybe you could order some seeds from The Farms seed store you could use a credit card EHHHH! That way you could by something quietly:)