If there is a problem :
I'd make sure the tail boom isn't bent first, check it very closely because it toesn't take much.
If straight, i'd replace tail rotor motor. Remove all the trim, having everything at neutral then re-bind it.
If you're just new :
I forgot to ask about your experience level Bob.
If you're really new to collective pitch helicopters for instance, at lift-off all collective pitch, hobby grade helicopters want to go to the left. If you have to add trim to a rudder the set-up is wrong. Also, none of them will fly/hover without constant control inputs from the pilot, constant. You can add some trim to get it closer, however as soon as your rpm is increased or decreased a little that trim amount is ineffective .
I would look into www.rchelicopterfun.com . Check out al his videos on YouTube too, they are free,starting with the first one. That e-book he sells though is amazing in how much useful info is in it.
Although the SR is a good looking little heli, it is,sadly,at best a poor collective pitch trainer. Money would be better invested in a top shelf simulator to get you going Doug