i traveled in youth hostels when i was a college student on a trip to Italy for 3 weeks. most of the hostels had rows of curtained showers.
But it was a little misleading. because most of the guys at the hostel had no problem standing around nude waiting their turn. most of us American guys tended not to shower until things thinned out in there a little. (the hostels as a rule were usually pretty crowded.) but even if we did have to be in there with the crowd to keep on schedule, it was easy enough to be modest yourself, with your towel on the curtain bar and drying off before opening the curtain.
bottom line, i wouldn't worry about it. its no big deal. if you feel modest, just cover up. but be prepared to be around others who have a different standard of modesty. there was some HS/university Spanish group there when we were there and they were all running around nude and horse-playing in Spanish. (first time seeing uncircumcised dudes for us Americans too. lol) Nothin you can do about it.