This is a fairly simple option, and this way you can even have an outdoor wedding that is still legally bonding!
Since 2015 civil marriages can now take place outside registry office - registrar will come out to your chosen venue.
This type of ceremony is quite short, usually takes 15-20 minutes. You will need two witnesses, who have to be min. 18 years old and have valid passports or IDs.
The registrar local to your chosen venue will have to see you once before the wedding. There is no minimum residency required, but you will have to submit a Certificate of Impediment beforehand (up to 6 months prior to the big day). This is a standard procedure for citizens of EU countries. For non-EU citizens from e.g. Canada, USA, Russia, or a middle-eastern country - the procedure is different as a Polish court permission is to be obtained.