Tybee Island has a private campground that is nice but it's basically a well manicured gravel lot. You'll enjoy the oak trees overhead though and the location to the beach life. https://www.riversendcampground.com/
There's another new campground near the I-95 interstate that is about a year old. Haven't been there yet Savannah Oaks.
Skidaway Island is nice! It's on the marsh so there are interesting walking trails. Nice statepark sites as well.
If you want the beach life then go to Tybee Island. If you want to be closer to the city, go to Skidaway or Savannah Oaks.
P.S. My inlaws live about 5 minutes away from Skidaway SP. We go there often to walk.
I was looking at skidway, tybee and DW Jekyll. We figured out Jekyll was to far from Savannah. I I think we are liking skidway because how close it is and it looks like larger cs and a nice tree canopy.
Skidway being in the marsh, we were wondering how the bugs are this time of the year?
We camp at Jekyll Island a lot. It's basically a private campground in a pine forest. Sites are close together. I think I posted a review of it somewhere on the portal. Best thing about Jekyll is that it has wonderful bike trails!
For Savannah...Skidaway is awesome...the sites are humongous and it is only a 12 minute drive to the downtown tourist attractions...there is also Fort McAllister a few more miles away which is also very nice but my recommendation is Skidaway. You should look here at the reviews http://popupportal.com/forums/georgia.315/