You can rent a car off airport from anyone and if you ask, they will send a shuttle to pick you up anywhere, e.g. at your hotel. In that way you can save the airport tax, around $15 and get your car when you are ready. They will also drop you off at the airport if you wish after you returned the car.
To get from airport to hotel, you can use a cab (around $10,if you tell the driver to go THRU town NOT use the tunnel). I refuse to tip them if they use the tunnel and tell them so,as that adds $4-5 to the trip.
Or ,by exiting the luggage pickup area on the opposite side of the cab stands, you can pick up a shuttle bus for $5 strip and $6 off strip casinos.
I rarely rent a car in Las Vegas. Free shuttle buses all over, you just have to learn where.