Can I buy a one-day bus ticket from the driver when I get on the bus ?

Some bus stops sell automatic one-day bus tickets, while others sell them at newsstands, with prices determined by time (60 minutes, 90 minutes, etc.). They don't charge based on the number of stops you take; we all bought our tickets with Czech crowns. After inserting the coins, the machine dispenses your ticket, which you can use to board the bus and stamp. If you don't have a ticket or insert coins when boarding, you can board within the time frame of your ticket and won't need to stamp again. You only need to stamp once, anyway.

Never bought bus tickets from the driver because of language barrier, but with chips in the bank card can directly swipe to buy. There are card swipe machines on the bus.

Some bus stops sell automatic one-day bus tickets, some are sold at newsstands, with prices determined by time (e.g. 60 minutes, 90 minutes), not by the number of stops you make. We all bought our tickets with Czech crowns by inserting them into the machine, which then spit out our tickets. We just had to scan our tickets when we got on the bus. There were no inspectors to check if you had bought a ticket or inserted money, as long as you did it within the time period of your ticket, you were good to go. You only had to scan your ticket once.

There are things for sale at the station, and you can use credit cards to pay.