After the tank is cycled you can start SLOWLY adding your clean up crew. It will likely take 6 months before you hit it's full size.
Figure out the size CUC you need by posting your tank and information, or checking one of several guides on forums. Then gradually build up to it. Websites that sale complete CUC packages are a bad idea except for established tanks. Those packages are far too large for most tanks, and added all at once will cause deaths.
Your first members IMO should be 3 margarita snails with coralline algae growth on their shells. They will carry coraline all over your tank.