Juana's (the local boat launch) is three lanes to launch, but don't use the third lane (furthest left as you face the water or S most lane) as it fills with sand and putting in is a pain as your trailer tires sink and recovering is just as bad for the same reason. I have a Raptor and still don't mess with it unless I am just launching/recovering my skis. I don't do it with the boat. There are bathrooms and trash at the launch, and there is a gas station for beer and fuel, but they charge more than on the mainland. Most gas station (mostly Tom Thumbs) have Ethanol free gas at the pump, if you use that for your boat. There is gas on the water at East River Smokehouse Pier, which is directly North across the Sound from Juana's. Ice is available at all convenience stores, and also in bulk at the ice machine on 87 and Laredo, across from the Tom Thumb. Two bucks for a ton of ice, which you can get in bags or dump right into your cooler.
If you are going to beach along the sound or any of the islands, bring a beach umbrella and some chairs. The sun is merciless. Two anchors are a must if you are not going to beach. Boating is huge down here, so there are tons of people doing the same thing and most are friendly and will give you your space on the beach. There are plenty of sheltered areas to pull kids (or adults) on tubes to get you out of traffic if you are bringing a tube or doing any towing sports.
Almost forgot to mention. The launch gets pretty packed on weekends, but usually moves fairly fast. If you want to dodge the rush to launch and get a decent parking spot, get there before 8 am and beach at Juana's. They have pretty good breakfast and you just wait for family to find parking once everyone gets up and moving. People will park in trailer only spots, but there is plenty of parking around if you don't want to get a ticket. I know I will call the Sheriff in a heartbeat if I see a car in a trailer spot with out a trailer if there aren't any spots open. Also, don't park in the sand if your truck can't get out. It looks tempting, but that sand in the parking lot is soft and I have seen plenty of people get stuck.
As long as you aren't going offshore, I wouldn't worry too much about a Marine radio. We have Verizon and our neighbors have AT&T and we have never been without service in the sound. If you want one for peace of mind, go for it. If you are going offshore, I would certainly invest. I have a Seadoo Challenger 180, so I don't mess with the Gulf as I have a low bow and waves love to break over it and get everything wet.
There is not a hose at Juana's or any of the other launches in Navarre. May want to bring a hose as well as there is no guarantee of one at your rental house. Use Salt Away or other salt rinse product on both your boat and trailer. I also hose down the back of my truck as well. I bring a water bottle to spray down my lug nuts on the trailer before I head out on my boat as well as I am paranoid after a broken stud. I also use salt away on the inside of my boat and jet skis as well, but my buddy has had good results with Simple Green and Salt Away to get rid of fish guts and blood on fiberglass.
You really don't need much for chart plotting. The sound is pretty deep in the channel, which is well marked, and you can see the depth come up as you get closer to shore with the bottom getting lighter. Jetboats have a real advantage down here as you can pretty much scoot over most the sandbars. They do shift after storms though, so even the best charts can't keep up. If you go too far West you end up in Pensacola, too far East and you are in Destin. Watch out for no wake zones as you get closer to Destin. They love handing out tickets to tourists over there. Also watch out for yellow and green jet skis as those are the rentals and they don't pay attention. The cheap pontoons are rentals as well and they really don't know what they are doing.
Other than that, it is a great time. If you run into issues with trailer or boat, PM me as I live in Navarre and have tools and space to work on a trailer or boat if needed. If you have any other questions, ask away. My family is usually out every other weekend as we live about six miles North of Juana's launch and LOVE the water.