Welcome to Oregon! And to the forum!

Since you have no experience, I have a couple of suggestions for starting out. First you might want to start by reading the articles on the home page of this site (left hand column). There are lots of articles on beginning backpacking and on gear selection. The gear lists were developed for summer hiking in the Cascade Range, which is exactly what you'll be doing.

Second, you should get your gear early enough so you have plenty of chance to practice with it in home. Practice camping in your back yard first. Out in the mountains late on a stormy evening is not the time/place to be setting up your tent for the first time or learning to use your stove. The same is true for keeping warm and dry in stormy weather--those skills are best learned where you can retreat indoors when things go wrong (which they often will--that's how we learn). I realize that practicing these skills--at least the keeping warm part--may be a bit difficult in Florida! However, the key to keeping warm is keeping dry, so work on the latter. Once you've had some backyard practice, a few weekend trips to the Appalachians will give you more practice and skills.

As for trip planning, in most years it is at least July before the trails in the Cascade Range melt out enough for extended backpacking. Last summer, it was mid-August before many of the higher trails were melted out, and some places didn't melt out until September. That was pretty unusual, but it can happen. You might want to pick August as your month. In a normal year, August will be pretty much snow-free and will also be less buggy.
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey