Replying to Going to mt hood in may, need ski bum advice

So I'm done exams next week, and before my summer job starts I'm going to make my first trip down to hood for a week or more. I'm grabbing Timberlines spring pass and then planning to live at the lowest possible cost for the next week+. Ill be driving down from BC, so I'm hoping to get an idea of what to expect when I get there. I hear theres 2 week free camping in the national forest? Is there specific campsites or can you just post up camp at any spot in the forest? I also have a wagon so if need be I can spend a few nights in the back of that. Also even though its free, do I need to get a camping pass or anything like that? My next big question would be nearest stores to buy food/ areas I can find running water for cooking/showering. Also with T-lines spring pass what areas am I available to ski in? (only public park or is there more areas..?) I'm really stoked on this trip but I just want to figure out anything I should know beforehand before just jumping into it. I have a soft date of arriving May 1st if theres anyone else in the area who wants to chill or camp with me. Thanks NS