The breadboard isn’t going to provide more IO pins but it will allow you to connect more than one thing to any pin, such as the 5V or GND pins. Usually you would use jumper wires to connect the 5V and GND pins on the Uno to the power bus along one edge of the breadboard and then connect that bus to the one on the other edge of the breadboard. If you’re working with multiple voltages you could use one bus for each.
As for how to connect things, there is a ton of information available with a few seconds of searching. Often you can use the Google images search to get graphical representations of how to connect any part to an Uno using a breadboard. So spend a little time researching and experimenting and after that if you some more specific questions come back and we can help you with them.
Thank you Pert for your suggestion. I don’t know what you mean by “working with multiple voltages”. I am connected to the arudino with USB port. But, I am not allowed to take my computer with the project. So, I will use a 9 volt battery as the power source. Will that be OK?