Bending moment at the support B is 0.
Therefore, the reaction force at support A can be calculated by following equation.

RA*L - w*L*L/2 = 0 and RA = RB

Maximum shear force occurs at both ends of beam and minimum shear force occurs at the midpoint of beam.

Maximum bending moment (MC) occurs at the midpoint of beam and it can be calculated as follows.

MC = (w*L/2)*(L/2)-(w*L/2)*(L/4) = (w*L/2)*(L/4)