Did I start my tank cycle all over again?
 

I've had the tank up for 3 weeks to a month. Gave my fish away to a friend, took some of the decor out and rinsed it with warm water and I did not take the gravel out, but I did add some more gravel on top of it and mixed it up some with my hand because it's a different color. Saw some of the food floating from the gravel to the top. Put the decor back in, the tank had some bubbles in it and was a bit cloudy like it was when I first set up the tank. I'm worried I started the new tank cycle all over again I really hope not. Would anyone know?

If this happened over one day, it is doubtful that the tank is re-cycling. Bacteria in the gravel would still be there and if filter material was not removed or cleaned under tapwater then you should still have a fair amount of good bacteria there as well.
Without fish in the tank however,or offering a pinch of food each day ,,the bacteria will begin to die off.

Thanks so much! I'll be sure to add a pinch in every night.
A question about the filter though, I thought every 3 weeks to a month we're supposed to tank the filter out and change it out with a new filter cartridge thing, and run tap water over it?

Do not run tap water over it. I change my cartridge once a month and use the tank water to rinse the cartridge.

Okay thank you!