First, welcome to the site, I hope you find everything you are looking for while here.
As for your questions:
Some of them do, some of them don't.
The ones that will work, will only work if you use your energy, intent, and will to make them occur. It isn't like you wave your hand and suddenly things go great. There is also the fact that if you do a spell for another job, you actually have to go out there and try to get the job.
Since you are new to magic, I suggest that you start with the basics:
Grounding and Centering
Don't freak out because this seems so long, these can be shortened to:
There are many members of this site who can and will teach basics, and many covens offer these as classes. I personally offer them of the members of my coven, however I don't teach those outside of it.