Chrck engine light on w/ codes C1130, C1155, PO868 & 0240 what do these mean????

Question

I have a 2010 Nissan Murano S. The cars been acting fine as far as I can tell other than a/c problems........freon full, new compressor & fan blowing fine but only outside or warm air....anyway I've had it in to the guy who replaced my a/c compressor 4x now and had an appt. to see him again when the check engine light popped on. I immediately stopped at Auto Zone to have a diagnostic done. The reading came back C1130 Engine Signal 1, C1155 Brake Fluid Low, PO868 Transmission Fluid Pressure Low and 0420 Catalyst Below Threshold Bank 1. After I got home my husband checked the transmission fluid level & it was a little low so we added not quite a half of quart, he checked the brake fluid and it too was low so we added some there too ( I do have all new brakes!). I still would like to know what these codes mean & what to do to fix them........of course everything hasn't been addressed so the check engine light is still on! HELP, PLEASE!!!!! Thank you!