Can I run 15,000 BTU air cond with RV plugged into my house?

If it is tripping the 20 amp house breaker obviously you cannot run the coach acnd without tripping. You can take a look at what else you may have on that circuit that could be disconnected and maybe reduce the load or more than likely you will have to get a qualified electrician to see what is required to install at least a 30 amp circuit.