Ciao Kiml,
All bus tickets here are sold not on the bus, with a blank area -- when you get on the bus, you put the ticket into the ticket machine which "obliterates" the ticket by marking the date and time on it. At that point, your ticket is valid for 90 minutes for local buses, or for the miles you bought it for with regional tickets. So tickets are made to be bought ahead of time, used when needed... so you can buy more than one right off the bat if you're planning to ride the bus around the city or area.
As for location, the tickets are either city (urbani) or out of the city (extra urbani) so you do need to buy the right type of ticket depending on where you want to go.... only the extra urbani require that you indicate where you're headed to since you cost is based on distance, but again, you don't have a date or time attached to the ticket so you can use it when you need to, by "stamping/obliterating" the ticket when you get on the bus. The ticket is valid for the specific trip you buy.
The local bus tickets are not based on destination, only on time. Once you get on the first bus, the timer starts ticking and you can use the bus ticket for the next 70 minutes after you first stamp it (only Florence gives you 90 minutes, all of the other major towns have 70 minutes).
The AT Bus website has all the info on types of tickets, bus schedules, etc -
https://www.at-bus.it/it/biglietti-e-abbonamenti/come_acquistare.html - but it is only in Italian. If you need help in finding out timetables, let me know and I can search for what you need.