Ive just started practicing with a metrenome and was curious on the terminology

If was playing 180 BPS and i was playing 2 notes per beat are those called half notes?
If i played 4 per beat are those quarter notes?

Am i better off doing 4 notes per beat on a slower bpm or 2 notes per beat on a higher bpm?
-Ibanez SAS36FM
-B.C. Rich Warcock Platinum Edition (my first guitar, noob mistake)
-Roland Cube-30