Prague has amazing public transport system, it is clean, convenient, and cheap way to get from point A to B, including from airport to city center. Prague public transport includes buses, trams, subway (metro), and some trains, boats, and also a funicular.
Tickets for Prague public transport can be bought in yellow machines, directly in trams and some busses, and more conveniently via PID Litacka app available for both iPhone and Android: https://app.pidlitacka.cz/
In the application you want to select Tickets > Buy a ticket > Prague
Tickets start at 30 CZK per single 30 minute ride for adult, but we recommend 330 CZK (14 EUR) 72 hour ticket, or 120 CZK (5 EUR) 24 hour ticket, if you plan to explore Prague a little bit.
When buying the ticket in the application, the ticket needs to be activated. When buying it from the yellow machine or a vendor, it needs to be stamped in the first vehicle you board using the yellow ticket machine (not orange), and then not stamped again if you switch vehicles.
When buying ticket in the vehicle using the orange machine, you don't need to validate again (you can buy up to 24 ticket this way, but not the 3 day ticket).
I can definitely recommend using the application, especially if you are carrying a battery pack.
If you prefer to ride by a car both Bolt and Uber operate in Prague.
Prague airport is close to the city and there are multiple bus lines going every few minutes from there to Metro (subway).
https://www.prg.aero/en/public-transport-buses
The busses leave from bus stops that are in front of both Terminal 1 and Terminal 2, and you most likely want bus 119, which goes every 7 minutes or so. This will take you to the green metro (line A), stop Nadrazi Veleslavin. From there you go to Muzeum stop, where you will switch to red metro (line C), and go to Pankrac. There you exit towards the shopping mall, and that is where Cubex and Panorama hotel is. The whole way takes about 1 hour.
There is also AE bus from the airport that is not included in public transport.
On your way you can exit metro on Malostranska, and visit one of the few nice gardens around (Valdstejnska zahrada, Vojanovy sady, Vrtbovska zahrada). You can take tram 1 stop to Malostranske Namesti, stop for craft beer in ROESEL and then walk over Charles Bridge towards Old Town Square.
You can also exit metro at Muzeum and walk down Wenceslas square, towards old town.
The closes metro station to old town is Staromestska (green, line A).
Prague main train station is directly on the red metro (line C), you will go from Hlavni nadrazi to Pankrac. It takes about 15 minutes.
Navigating Prague Metro is simple. There are only 3 lines which cross each other close to city center. Every station has a big table of stops in the middle, and on both sides.
Just like this one:
https://www.metro.cz/tiskni.aspx?r=metro-praha&c=A121011_143615_co-se-deje_ava
Florenc is the stop on which you are. You are on line B (yellow line), and you can transfer to C (red line) directly on Florenc. If you want to go to Mustek (and maybe transfer to green line A), or go to Karlovo Namesti, you need to go to the platform on the left. If you want to go to Krizikova, or Palmovka you need to go to the platform on right.
Both platforms will also have similar tables, on the left platform all the stops before Florenc will be gray (Krizikova, Invalidovna etc.), and vice versa on the other side.
Your ticket is valid in zones P, 0 and B, those zones span almost whole Prague, and go way past the last stop of Metro, and also include airport.
With your PID ticket you can use Metro, all trams (except for historical tram), buses, P boats, and also funicular to Petrin (https://pid.cz/en/petrin-funicular/).
At night there are night trams that start with 9*.
Google maps are pretty great at finding transportation and points of interest in Prague. The only downside is that they often take you to the closes tram station before your destination and then you need to walk 400 meters, rather than taking you 50 meters past your destination.
The local app we use is IDOS https://play.google.com/store/apps/details?id=cz.mafra.jizdnirady&hl=cs&gl=US&pli=1 which is more accurate than google maps, and knows about delays.
And for maps you might download Mapy.cz which usually give better walking directions than google maps.