Ahoy Matthew, congrats on the new boat. It is a great family activity, you'll make memories. Get a proper boat safety course for you and your family members.
You'll get both sides of the wet slip argument, and I've done both setups with my boat. For the last 5 years, we have used a covered freshwater wet slip for 3-4 months, and stow her the rest of the year in a very dry climate. Change out the bellows at least once every 2 years to help avoid a leak and sinking. No doubt, you'll get more time on the water with a slip, both in an individual outing and across the season.
Thus far, I've avoided blisters. Could be luck, could be our dry climate for majority of the year when she's on the trailer. Either way, I'm about to invest in a lift.
Despite it's intended use, all gelcoat is porous. The simple blistering explanation (sans chemistry) is that water eventually, over time, enters via the gel, and gets trapped between the fiberglass and gelcoat layer. In the process of trying to escape, blisters can form. As suggested, proper bottom coating can help protect the gel and delay/avoid blistering, but it can cause a negative hit to the value of your boat. So can blisters.
Many boats sit in the water over much longer seasons, and over many years with no issues. Others swear by trailering or lifts to avoid the risk as well as protect the craft from rough water and potential damage from banging around in the slip. You can also expect some damage from constant trailering and dry stowage, even if careful, stuff happens.
The real question is how lucky do you feel?