I'm heading to these few cities with 2 kids in June:
Istanbul, Bursa, Kasudasi, Ephesus, Konya & Capadoccia.

Besides Istanbul which I understand I can get around by walking, taking buses and trams, would I be able to move around easily using buses and trams in the other cities? Hiring a tour guide with car will cost us quite a bit and we wish to keep our cost low. And we don't want to self drive as well.

We will need to hire a van to drive us inter cities though. What is the best way to go about this? Could someone direct me to the right place to do a search?

Thank you!

You have to rent a car for places other than istanbul and bursa. For example, in the Cappadocia region, public transportation vehicles only work at certain times and on certain routes. So a rental car is a must. You can use airline-buses between all these cities and touristic areas.

A professional guide can both drive and give you historical and archeological information. The cost may increase a little..

It is possible to reach all of these cities by plane, bus and train. But with kids it can be difficult. That's why you should consider renting a car.

There is an airport in every city in turkey. There are flights to all cities from Ankara and Istanbul... and there are flights to Istanbul and Ankara from all other cities... You can travel between all cities by bus. 75% of cities have railways...

We were in Cappadocia for three days and did not rent a car. We stayed in a wonderful cave hotel, Esbelli Evi. We simply asked them to arrange a car/driver to pick us up, drop off at sites like the underground city and pick us up again. They seemed to work with one or two drivers to handle their guests because the driver was coordinating pick ups for others all during the day. It was not expensive and worked perfectly. We did that on two of our days there.
Even arriving very, very late, there were shuttles waiting at the airports to drive guests around and drop them at various hotels. All of this saved a lot of time getting to/from car rental places and at the time, came to about the same cost. We walked to local restaurants in the evening, but our hotel also brought food if we asked and it was fabulous.
In Kusadasi, I don’t know if this is still current information, but there was a tourist place where you can book tours, guides, vans, etc, Outside, on the street corner right by the tourist center, there were drivers with vans looking for people to form groups to go to Ephesus, etc. We hung around until we had a van full and arrived at a price per person. It was great because we did not have to look for parking, worry about driving, etc. That would be fine for older kids and teens, perhaps not good for little ones. Be sure to have water with you.
In Istanbul, you can easily walk a lot of places, take trams, etc. We took a taxi from the airport to the hotel, but there is also a super cheap shuttle van to the airports. Our hotel arranged it for our departure.

Thank you all for taking the time to reply! It's very useful information for my planning From the look of it, I think a private hire or self car rental is necessary to save time and convenience for my trip.

How was self driving like in Turkey for you?