Hello, there. Welcome to mannis

.
Newcomers is always a target for players with higher wages. A good advice for not getting shot all the time is to hide, which can get a bit boring after a while. So I suggest you make some friends by giving those who are killing you items. Like cakes, full suit or weapons. And be sure not to whine when someone kills you, like swearing at them. That will just propably make you get killed even more.
A good way to earn a lot of money fast is to rob. Rob vendors like there is no tomorrow. But the trick then is to avoid the cops. If you're good at bunnyhopping you can pretty much outrun them, or you can hide in one of the secret places in the map. You can either wait it out untill your crime is 0, or turn yourself in when your crime is below 100, because then the cops have to uncuff you after they've cuffed you.
To make your wages higher just simply play alot on the server. You can type /rprank in game to see how long it is untill you get 6 wages.
And as a answer to your last question about how to become a cop I recommend you go to this topic
http://www.mannisfunhouse.eu/forum/index.php/topic,1116.0.html and be sure to read the instructions in Gpoints first post.
Regards Freddern