You'll want to do some research on how to select a good camp site, water treatment options, and backpacking stoves. Think about whether you want to cook or boil water and rehydrate (the latter is lighter and not always as boring as you think, especially if you look up freezerbagcooking.com).

If you're not going to make a habit of backpacking, renting equipment from REI is cheaper than investing a ton of discretionary income. They have some nice lightweight tents, sleeping bags, pads and poles you can try out.

I recommend a map and compass regardless of intent to stay on the trail. Walking 100 feet from the trail to dig a cathole to contribute to the general biomass then getting turned around is not unusual for me, and I have a pretty good sense of direction. Take whistles and come up with a simple code - two long tweets means "I'm over here" and three short blasts means "Help, I'm lost/being chased by a lion/floating down the river, come quick!" for example.