My son fell & hit his head on the edge of a wall, he has a cut but not too deep. But its bleeding Is he ok, medical attention needed? What should I do

2 problems. Assess the cut and if the edges are separated or the cut is deep he may need sutures. Did he loose consciousness, was there any vomiting or has there been a change in his behavior? If the answer to any of these questions is yes, he needs to be checked immediately. Watch him closely and have him assessed for any of your concerns.
Bleeding. Hold continuous pressure with a clean moist(cold water) clothe for at least 5 minutes. Scalp and face cuts bleed a lot. If the bleeding stops and he is behaving normally a simple bandaid will due. If it does not stop bleeding go to your local urgent care.
Head trauma. Clean the area really well with soap and water. If cut is very shallow then there's no need to be seen. However, make sure you check his neurological status. Look at his eyes make sure it follows you well. IF child too cranky, not acting normal then its better to have him checked out. If he's throwing up and seems to be very sleepy have him checked out at ED esp if he has a big gaping wound.
Seek medical attenti. After a head injury and with continued bleeding it would be good to take him to the emergency department to be checked. If he is bleeding quite a bit he may need stitches. Please take him right away to the emergency department or to an urgent care center.