"Winging it" in Florence for accomodations?

" Since its June, high season are options more limited? " Gently speaking , an understatement .

In my experience, the good quality, inexpensive hotels book well ahead of time (even in non-high-season), so you're likely to pay more for lower quality if you don't reserve hotels. Don't know whether hostels differ.

There are hundreds and hundreds of accommodations in Florence.
You can always find accommodations in any major city the day ahead if you have the internet access with you; a laptop or notebook. If you arrive during business hours, the tourist information office across from the train station will find you a room for a couple of euros. Roberto's from Florence, and maybe he'll chime in on your info request.

June is high season so some hotels/B&B may be sold out for some days, however you will find accommodations somewhere else in the same price range. There are several thousands hotel rooms in Florence alone. Either online or at the tourist office you'll find something even the same day. I don't know about hostels since I'm not familiar with them and I've never been in one. I know where the one in Florence is, but I don't know how big it is or if it gets sold out often. I usually travel to Italy in June/July and I usually reserve a place one or two days ahead only. Before the Internet era, I rarely made reservations, I just called the same day and always found a place within the first 4 or 5 calls even in the busiest periods. Nowadays with Internet just do a search and something will come up available on the same day.

I understand that it will be much more challenging to find a place to stay without reserving well in advance. I wanted to get a few opinions, that's all. I may talk with my friend and possibly encourage locking down some dates and look for places early. I appreciate any and all feedback, thankyou

As Roberto suggests, use the internet when you know you're ready to move to the next place. A booking site like booking.com can be very helpful, even if you decide to do the booking directly with the hotel/B&B. You can also probably get recommendations from the staff in one city before moving to the next. In my experience, apartments tend to be booked further in advance and some require a minimum stay.

Actually June is busy in the art cities, but not as busy as some days in Spring. The busiest time of the year, by far, is the last week of April. April 25 is a National Holiday (Liberation Day) and May 1 is Labor day throughout Europe. If Easter is around that time then it's even worse. Easter is also busy. The last week of April is the only time of the year where you might find challenges to find a room in the city center anywhere in a city like Rome or Florence. That is the only time in my life where, a few years ago, I couldn't find a room anywhere in Rome but at the E.U.R. Also some years there might be special events (such as the 2000 Jubilee year in Rome). June is busy because of foreign tourists, but Italians don't visit art cities (Florence, Rome, Venice) as much during that time because it's already too hot and they'd rather go to the beach instead. Also in June there are no school trips anymore. If you go in April or May there are hordes of European high school kids on school trips visiting the art cities, and they take up a lot of hotel rooms.