Can't use rcs thrusters

You forgot to add mono propellant fuel. It happens.

@Ammconn You're very welcome, feel free to ask away if you have any more issues. Take care! :)

@yopo Changing the propellant worked! I'm new to the game thanks!

Simple things I can think of off the top of my head include:
1. Make sure you have RCS fuel (monopropellant) in a fuel tank attached to the RCS thrusters.
2. Make sure (in the part settings) of each RCS thruster nozzle that it is set to consume enough fuel when it fires to be of sufficient thrust to move your craft.
3. Make sure the RCS nozzles are near the top of your craft (higher than center-of-mass) to give them more lever-arm force (torque) thus making them more effective.
4. Make sure your RCS nozzles are evenly spaced around the body of your craft, an easy way to do this is use part-mirroring on one of the RCS nozzles to make it repeat so each side of your craft's fuselage/body has an RCS nozzle on it so thrust applied is even.
5. Make sure the RCS nozzles are in an activation group that is activated when you want to use them, to edit activation groups, open the part settings of your command pod or command chip in the designer/editor.

Hope that helps!