Radar vectoring means giving the pilot specific headings to maintain the desired track. When "under vectors" or "under radar control", it means that a radar control service is being provided, i.e. the PIC must do what he is told by the radar unit and the ATC assumes responsibility for separation and terrain clearance in flight, providing bearing, distance and height information on known conflicting traffic. Some services will also provide advisory avoiding action.
Thus, the PIC when "under vectors", should follow the ATC's instructions.

In a radar environment, heading information given by the pilot and heading instructions given by the controllers are in degrees magnetic.

Minimum Radar Vectoring Altitude (MRVA), also known as Minimum Vectoring Altitude (MVA), is the lowest alltitude, expressed in feet AMSL, to which a radar controller may issue aircraft altitude clearances during vectoring. MRVA allows the ATC to vector and descent an aircraft below MSA to achieve VFR or to join a procedure.

Therefore, the pilot should turn left to head 285°(M) and descend to 2300 feet. The minimum radar vectoring altitude may be below MSA.