Well he is jsut a baby and will want your attention all the time
your his new mom and he is behaving like a puppy does... He is going to whine and cry for you, and when you guys give in he learns to do it again so he can go in your bed. Also he wants your comfort and warmth. Consistency is the key. If you do not want him in your bed then place a blanket, a shirt with your smells on it, and a small heated blanket, something that he can stay warm on.
Son't give into his crying too. It teaches him to behave more like that to get his way.
When you start school how long are you going to be gone? If it is too long then somebody needs to check on him. I would not leave him home alone all day long by himself.