Can I use a 30 amp breaker instead of a 20 amp breaker? The breaker keeps tripping when I use the sweeper and the portable electric heater off the same outlet.

Only if the wiring is #10, if the wire is #12, as it should be for a 20 amp circuit, you take the risk of overloading the wire and this is a fire hazard.

The circuit breaker is doing it's job because the circuit is being overloaded with the appliances you are trying to run at the same time.