Need assistance for homemade dc motor
The brushes should be energising the windings that point perpendicular to the magnets.
rotate the motor slowly and observe the angle each coil will be energised at then move the magnets or brushes to compensate.

the coils should be polarised the same check that the current flows consistently clockwise (or anticlockwuise) when viewed from above for each coils facing up. and that it flows parallel in th same directions in the coil below it

Make sure that you are not over-loading your power supply. put a 8 ohm (or greater) resistor in series with the motor, use a buck converter with input current limiting, or use dry-cell batteries instead.