homeless and with kids

I have a question. I live in Massachusetts. we have become homeless. not due to anything like drugs or drinking but due to we just can't afford any places. we've tried getting into shelters and things but we've been turned down because the person we were staying with won't help such as writing a paper saying we are temporarily staying with them and why we can't continue to stay with them. unless there is a danger to children or DV in the home, ppl pretty much won't help. my son who will be 6 in August starts school in September. if we were to be staying at a hotel while we save and find an apartment, Can my son still go to school? or does staying at a hotel make him exempt? since we won't have an address. TYIA