Our kids have been traveling for years, starting at 7 months old! They have been great travelers! They are now 9 and 12, so when we started all this there was no option for the discounted tickets.
We would try to travel when the flights were less crowded, like at 8 AM. We would book an aisle and a window where there are 3 seats across and cross our fingers that no one would be in the middle. That worked all but 1 time. We ALWAYS brought our car seat, and we had to check it at the gate just that one time.
Soon after, the option of buying an infant seat at 50% off started, and we always took that option. Yes, we hated spending the extra money, but we looked at it as a major safety issue, and being in a car seat on a plane is the safest way for a baby to fly. (You can research this, as I did.) Also, your baby no doubt is used to spending time in a car seat. We found that our kids were not restless during the flights and were quite content to stay in their car seats, someplace very familiar and comfortable for them. Sometimes they slept on flights, sometimes they didn't, but they always were easy travelers, and I think their familiar car seats was a big reason for this.
Keep your child drinking on take off and, even more importantly, on landing, to avoid any ear discomfort (which would lead to a screaming child). I would hold off on the liquids right before a flight so that my babies would be thirsty on take off. Then I would hold off as much as possible during the flight, so they will want to drink a lot during the longer, sometimes more painful (to the ears) landing process.
I nursed my kids, but not on the flights, although I know a lot of people do do that. I brought pumped milk with us for them for the flights; as much as I really wanted to nurse on the flights...help with the ear thing, as well as the normal routine...my husband and I felt it more important to keep the babies in their car seats, especially for the take-off and landing...so we fed expressed milk in bottles. (I don't know what the TASA regs are on all that now.)
I always brought both familiar and new toys for the ride there and the ride back. I used to wrap them (maybe not at 7 months) to add to the excitement.
Also, travel with lots of extras...diapers, milk, snacks, etc...just in case of flight delays.
Additionally, international flights often reserve bulkhead seats for families with infants, and they will put "sleeping cots" in front of the seats, attached to the wall. I don't recall seeing this in the U.S., but I may be wrong. A bulkhead seat will give you more leg room. Often, however, the arms cannot go up on the bulkhead seats, between the seats (at least on the larger, international flights), so as your child gets older you may not want that if you want him to be able to cuddle against you during a flight!
Good luck on your trip!
To what part of FL will you be traveling? We travel to FL every year and I can recommend some great places for you to go to with your little one!
Have fun!