Florence Airport to Santa Maria Novella Train Station Tram

Yes.
Exit to the outside, turn left, walk two minutes and the tram leaves from there.
The stop you will get off at is Alamanni; the next stop which is the last, is UNITA.
You can get off at either and you’re right by the SMN Station.
The trip takes 20 minutes, and I believe now you can tap in with your credit card to get a ticket.
Each person would need their own card.
If you want actual tickets, there’s a machine on the platform.
An easier way though is to buy tickets in the gift/candy/tobacconist shop just before you leave the airport.
Less crowded than the area around the machine.
If you have paper tickets you must validate them in the machines on board the tram to avoid fines.

https://www.gestramvia.it/airport/?lang=en

The above is correct except for the part concerning the UNITA stop. After the ALAMANNI/SMN stop, the T2 line loops around the station and stops at the other side of the station (VALFONDA), then goes toward the Fortezza, then onto Viale Lavagnini toward Piazza della Libertà, and down to Piazza San Marco. So depending on where your accommodations are, it might be more convenient to stay on the train past the station and all the way to Piazza San Marco. The UNITA stop, which used to be the last stop of the T2, now it’s the last stop only for the last runs, after midnight.

Thank you both - this is exactly the kind of information that I needed!

Thanks Roberto , for the correction. :)
Good to know you can now go further on that line.