Dear Dino
YES you should use the rudder and ailerons in a coordinated fashion to make turns.
Do you need to? Well, most planes will get around without it, but why not do it right?
Warp drag, or adverse aileron yaw as it is now known is a real thing. There are many books to understand why the rudder is used. May I suggest that you:
buy and read "Stick and Rudder". (though he makes a case for designing the rudder OUT of planes)
and find and see the film: "The Winds of Kitty Hawk"
The Wright brothers, the true inventors of the airplane" developed a method to coordinate turns using aileron/wing warping and rudder...it was this method of control that allowed for airplanes to work...it is the basis of their patent on controls of planes.
IF you are taking lessons, your instructor isn't doing enough for you.
Rudder is used for many applications including crosswind landings, engine out procedures in most (not all...see multi engine planes like C337, Lear FAn, BAC Lightning) multi engine planes, and to counter adverse aileron yaw and in swept wing planes: dutch roll.
Rudder can even be used to ''slip'' a plane into a landing.
IF you truly want to fly a plane without using rudder, see the Ercoupe/Aircoupe built without rudders as a safety plane (some have been modified) with the only pedal on the floor being for the wheel brakes.