There are several ways to getting around in Macau with the cheapest option being walking and the worst being taking a taxi.
Walking
Walking is definitely the cheapest alternative and the best way to explore Macau. You will discover hidden gems and different spots. Macau is really small, and many of its attractions are close to one another, so you can easily explore them on foot. To make it easier on yourself, plan to visit attractions that are in the same area.
Public Bus
The public buses cover scenic spot in Macau. Problem is, all public bus stop's names and routes are all in Portuguese. I was using an app that helped me with the bus routes before, but on my last trip, I realized the bus routes have changed and the app was no more useful. So I used google map which was extremely helpful. Make sure you have some coins for your bus fares as you’ll have to pay exact or forfeit your change.
Depending on your location the fare is usually between MOP$2.50 - MOP$6.
Shuttle Bus
All the major casinos in Macau provide free shuttle bus services for their guests to most major transit points and attractions. You gone have to be a bit sneaky here, but if you plan your route well, you can end up using only the shuttle buses to get around Macau. No one will check if you are a guest. So figure out which hotel is the closest to where you want to go and hop on a shuttle and act normal.
Taxi
Getting a cab is the expensive choice compared to all the other transportation options in Macau. If you plan on taking a taxi, look for the yellow and white taxis. They are inexpensive and can be found almost everywhere. All the taxis operate on meters, they charge for luggage and there is surcharge depending on location.
You can get more information on taxis and fees here.