This is my initial dotmap based on available recon.
Red dot
Advantages
(1) Immediate access to 2 BG, improved production rate.
(2) secondary border gets cattle(+2food) and wine(+1food). With 1 more citizen producing +2food, this is a 4 turn settler factory.
(3) Decent number of hills for long term production.
(4) River access for extra gold and no aquaduct.
Yellow dot
Advantages
(1) at least 2 BGs in borders, 1 is immediate access.
(2) good number of hills to offset production loss due to coast tiles.
(3) Hill defence, across river defence.
(4) Sea access.
(5) River access for extra gold and no aquaduct.
Disadvantages
(1) Unknown tiles, need more recon.
Green Dot
Advantages
(1) Decent spot with wheat and good mix of plains+grassland. Plains irrigated gives quick improvements for production.(irrigation takes 4 turns as opposed to mining of 6 turns)
(2) Decent number of hills to offset lose of shields from coastal tiles.
Disadvantages
(1) No river access, need aquaduct.
I would settle in this order of red, yellow and green.