I am a recent graduate in Physics (Bachelors), and will be entering the job realm in a couple of weeks. I have notice many places require training where I may have to leave my family to obtain. I also have a child on the way (like possible today). I don't want to leave my girlfriend during this time as she is still in college taking courses at the physical location. Yet, we need more cash flow into the household. Any advice on going about this situation (like a way to postpone my training yet still obtain the job)? I am specifically looking into the military defense sector, if that helps any.
I'd suggest looking for a job in your sector that doesn't require training where you would have to leave your family - when in doubt, you can ask during the application process.
It seems perfectly valid to ask before or during the application process where and for how long the required training will happen. There are numerous reasons why some people can't leave their family for a longer period of time, and taking care of your baby and girlfriend is certainly a good reason.
Alternatively, look for some kind of temporary job where at least you can make some money and possibly gain some relevant work experience without leaving your family.
If your goal is making some extra money without leaving your family, you could try to find some other job that is perhaps not your dream job, but would satisfy both of your requirements. After maybe a few months, when you feel more comfortable with the new situation, you could still start looking for a "real" job.
Ideally, if you pick up a temporary job, it would be somehow related to the sector you desire to work in later on. But if that is not possible, it still won't hurt your career.
Any advice on going about this situation (like a way to postpone my training yet still obtain the job)?
Best advice I have is to be upfront, open and honest about the situation - see what they say.
Some employers will naturally be more accommodating than others, depending on how critical the training is to your role and how realistic it is that you get by without it for the first few weeks. They may not even want to do it right away, so it might not present an issue.
If it does prove to be an issue, some employers may also offer you to delay your start date - depending if immediate or long term cash flow is a concern, that may be an option you wish to take (you may sacrifice a month's salary, but you'll know that you have a job to go to after that, and don't have the pressure of interviews after the baby is born.)