HOSTILE TOWARDS HOSTELS

So I got an email back from the school. The language barrier might be preventing me from understanding the email properly but it seems that they are saying that I can't move in until the 18th because of permission with my VISA. But it's my understanding that I can be in the country for 3 months without a VISA so I'm not sure why that would matter. I don't want to keep asking them about it though. I feel like they've already done enough. But I also don't want to wait until the 18th to go to Poland. So I can either stay with a friend or stay in a hostel. But I'm totally afraid of hostels. Especially since I have all my stuff with me and I'm just not sure where to go and what to do with all that. I"ll have to think about it.