Thank you, everyone! I appreciate you taking the time to respond. Sorry some of you are going through it/have gone through it, too.
I always thought it was a secondary infection type thing, but then read some information about pneumonia (specific) bacteria, so was confused. This clears it up for me.
My oldest got it when he was working 5 hrs a day with kids, pulling a 15 hour college schedule, which includes an EMT course, and doing 12 hour shifts with EMTs to get his hours and patient contacts in, so it's no wonder he came down with it.
My youngest is pretty healthy and not physically or mentally stressed right now, so I'm not sure why he has (if he has), but we'll find out for sure in a bit. He has a doctor appt at 10:00.
It started Monday night. He said he just didn't feel good. Said his whole body was sore and he felt so weak. It was a long day and I thought he was just tired. Tuesday at school, he continued with the tired feeling and started coughing a little. I'm sorry to say I thought maybe he was just trying to mimic his brother's symptoms to get out of school.

There was no fever then. Yesterday morning he woke up and looked and sounded terrible. Was coughing hard consistently and said his throat hurt some, but mostly he was just so weak (kept emphasizing that, rather than the cough), then the fever came and I called the doctor. I don't know if he had night sweats last night. He felt a little wet (still hot) this morning, so maybe so.
Here's another question: my oldest's doctor did not give him an inhaler or cough medicine. She said she wanted him to cough as much as possible. He has an appointment in two weeks to get another chest X-ray, but he is still coughing a lot (though feeling much better). He had a car accident two days ago (sigh) and the doctor at the ER, said he still heard the pneumonia. Should he go back to/call his doctor, or just wait for the chest X-ray?