Easiest one - gearing - something around 36x21. Then you can go bigger/smaller from there when you've found your preference.
imo 26" is god for polo. Others have mentioned the limited choice of good polo tyre in 26"
Frame size - I'd say 1 size smaller than what you'd normally ride. If you normally ride a 56cm frame try a 54cm. For this I'd say try riding other people's bikes to find something that works. Most people won't mind you having a go to find out what's best for you.
Easiest one - gearing - something around 36x21. Then you can go bigger/smaller from there when you've found your preference.
imo 26" is god for polo. Others have mentioned the limited choice of good polo tyre in 26"
Frame size - I'd say 1 size smaller than what you'd normally ride. If you normally ride a 56cm frame try a 54cm. For this I'd say try riding other people's bikes to find something that works. Most people won't mind you having a go to find out what's best for you.