I encourage everyone to download Signal. This is where the group conversations will be held. I'd also check if your phone carrier has coverage in Colombia, otherwise you can explore options to purchase a SIM card. p.s. T-Mobile has free unlimited 2G in Colombia
Most establishments accept credit card, but street vendors only accept cash. Expect to exchange/withdraw some cash. 1 USD = 4,800 COP
There is Uber in Colombia and it operates in all major cities. Traditional taxis are available, you would need to haggle the price beforehand. Public transportation is going to be widely available in the cities we visit.
No dress code. Bring comfy clothes, It'll be Colombian summer when we visit. I'd also recommend at least 1 button down for our fancy nights out.