The key to training is to “click’ and ‘treat” never say “no” and never punish. Just ignore the behavior you don’t want and reward the behavior you do want.

You ‘shape’ behavior by rewarding behavior that is close to what you want, and then more towards what you want

Beg is a good first trick.

I have a clicker somewhere when I was trying to train Pepe not to lunge and bite me but I never had the time to actually try this.

Let us know how it goes – I bet Cotton will look cute doing some tricks. He might even turn the clicker on you to get you to do some tricks too :~)