There are normally plenty of taxis waiting outside the airport at Wroclaw. The journey from the airport to the centre of town is only 15 mins depending on the traffic. The Radisson Is by far one of the best hotels in my opinion, bieng some 10 mins walk from the centre of town & approx 30-45 mins walk from the staduim. Taxi Journey is only 10mins from the staduim.
The stadium is not within walking distance of the track.
I hope this is useful