Reserving or booking hotels, airbnb or hostels in Poland

I have a question as everytime I traveled anywhere in Poland or europe either the company set it up I tried applying for or I used a tourism agency to do the work, but if I myself want to say go to a soccer game in another city in poland or even country in europe how do they set it up? do the fans have to book them ahead of time and reserve them or do they just go to where they play and shop from one hostel or hotel until they find one they want? what are the chances the rooms will be booked if you try on the whim getting a room at night after the partying, and drinking and soccer game is done?

I ask befause zi want to start traveling with the teams. Also, if you reserve can you change your mind and not pay or do they charge you right away or just get your credit card i formation? I also ask because zi want to go on a bike trip to curovian strip and i dont know which of the small towns on that strip to reserve ahead of time so I would rather just do it that day but if i reserve in one of them can i badk out without paying and find a diff room?

ever heard of booking?

yea Im seieng it but can you book stuff that day? or does it usually have to be ahead of time? Like how would you know when youre traveling with a team whether they will have options or space but if you book ahead of time you may be away from the action or end up picking a spot the other fans arent staying at.

whats the standard rule of thumb, book esrly and reserve for best price or last minute?