You are the GM, head coach and all the other coaches. So unless you have another coach playing with you(many have done this), then you do it all.
You recruit all the players.
May I suggest you find the help file that explains what attributes(strength, speed, etc) are important for which positions. Otherwise you may as well pick names out of a hat. Then look for players at that position that you need with the attributes you now know you need for those positions.