Is it possible to directly couple the motor to the wheel? How do I do it? I need help! 😀
You could use an off-the-shelf gearmotor. These have the gear reducer built right in.
www.mcmaster.com and www.grainger.com are two good sources in the US for general widgets and other hardware. Also msc-direct.com.
You can attach a wheel directly to the motor output shaft using a keyed hub with a set screw. Keystock is available at the above links. Watch your loads, though. Motor bearings are designed to support the armature on the motor, not wheels or other things that may be added externally.