I have 20 years of backpacking experience, mostly in the Appalachians. I can give some equipment suggestions if I know more about what you are planning to do.
You need to give very careful consideration to boots and clothing. Whatever boots you select, be sure to wear them as much as possible before setting out on the trail. It's a mutual adaptation thing. You need to get used to the boots (and locate potential hot spots), and the boots need to get used to you (i.e., broken in). As for clothing, it's an unfortunate fact that cotton is a very poor choice for backpacking because the fibers absorb water (including sweat) like a sponge and take forever to dry out. This is not only uncomfortable but can lead to hypothermia. I.e., you may need a whole new wardrobe for this sport, and that can involve significant expense. Fortunately, places like Walmart and Target do have some items which will work, but one needs to pay very careful attention to the composition of the fabric.
Personally, I take an ultralight approach: the lightest possible backpack which gives adequate support for the load, an ultralight goose down sleeping bag (a controversial choice which works for me), and a bivy sack (with or without a tarp) instead of a tent. To me, an enjoyable hike is far more important than having all the comforts of home.
To put this somewhat on topic, for an ultralight whistle, take a Little Black or a Guiness.
