I drive for Uber and I have commercial insurance, when I am not driving for Uber, can I give tours of my city to guests?

The laws concerning Commercially insured vehicles varies widely by State and City.  Most major cities would require a license of some sort and fee's would be involved.  You would most likely need a "permit" to operate and in all probabilities you would have to establish a corporation of some kind with a business name.  (which could be your name).

Which begs the question, why do you have commercial insurance rather than just adding Rideshare onto your existing policy which costs MUCH less?  Surely you must already be a part of a driving/transportation situation in order to be paying for commercial insurance?  Possibly you could do private rides under the guise of whatever company that is and avoid the additional expense since you're probably only going to offer the private ride service on a very select basis.