Vectors are quantities that have a size and a direction.
Examples: Displacement, velocity, acceleration, momentum, force.
Scalars are quantities that have a size but no direction.
Examples: Temperature, cost, speed, length, height, width, age, energy.
Scalar quantities have only magnitude. Vector quantities have both magnitude and direction. Temperature and volume are scalar because they don't have a particular direction.
Velocity and Force (because acceleration actually has a direction) are vector quantities.
Velocity is the combination of the scalar quantity of speed with a direction for that speed. Speed is always a positive number but velocity can be negative and positive because it has a direction.