There are several possibilities for accommodation in Turku.
One possibility is the “ship hostel” (Laivahostel S/S Bore) which you can find here.
The bus line no. 1 (which you can take to the venue) has a stop there.

We can also try to get some private home accommodation for some people at least, where people can sleep on spare beds, couches and such in private homes. These are, unfortunately, more or less far away so a bus or a car would be needed. Please state in your registration email if you are interested. No guarantees can be given, unfortunately.