My husband and I are planning a trip to Sydney in September. I am wondering if the public transportation in Sydney is easy to use? Is it fairly easy to go from the CBD to the north side of the Sydney Harbor Bridge? Thank you in advance!

We live in Australia but in a different state. Sydney uses the Opal Card for transport. You may be able to use cash or a credit/debit card, check on the link below.

On our visits to Sydney we always found it fairly easy to get around. There are ferries you can use with the Opal Card, it makes a lovely day out on the water. Trams are fairly new to Sydney I believe and the only thing I found a bit unusual is you tap on and off but the reader is not on the tram, it's on a post before you board. So tap and then hop on the tram. There are buses, trains, trams and ferries and it all seemed to work well. There are some great coastal walks in Sydney too, we caught the bus from the city area to Bondi Beach and started a walk there (2 hours along the coast, just gorgeous) and caught a bus back again from Coogee.

https://transportnsw.info/tickets-opal

In addition to the Opal Card, passengers can tap on & off with their tap & go credit cards. One card per person, no double tapping.
Here's a map of Sydney which may be useful for you:

Sydney map: https://goo.gl/maps/PFmeA45BAKXruh4F8