Welcome to TNet!
Any machine can find metal, just some give more info about your target, other than "here it is!"
So, start with mid-priced machine with good reputation AND warranty/service...!
That will give you plenty to figure out, in operation, BUT you have got to learn all about it anyway,
in order to become a successful detectorist.
In the meantime, your digging skills will get better, too.
Be SURE to get a PINPOINTER as well, it is a very important tool - ask anyone...!
Good Luck and Happy Hunting!