The player's position is point1. Enemy's position is point2. First you'll need to find the difference between the x1 and x2 and y1 and y2 (I'll call these xd and yd). Then you can get the angle between the two points by doing theta = atan(yd/xd). Now you should be able to get the new x and y (which I will call x3 and y3) by using the angle and the distance you want to travel where x3 = (d)(cos(theta)) and y3 = (d)(sin(theta)). Move the enemy to (x3, y3).
d is the speed the enemy is moving per update. You might have to mess with the signs to get the directions right (i.e. if the enemy moves in the correct x direction but wrong y direction then change the sign on y).
Hope this helps!
