It is okay for a woman to marry a much older gentlemen, as long as he can provide for her. By bus: Don't walk alone at night or in slum areas. You have endless options to find different kind of clubs, bars, pubs and lounges. It's a common misconception that drinking tap water in Colombia will give make you sick.
You need to download WhatsApp because normally the conversations will continue there.
You can wear casual clothes depending on your set plan. If she appears you can go to a restaurant, cinema or for a drink. It's very common that people who are working in online businesses are enjoying the freedom to live anywhere in the world because the work can be done anywhere. During the day girls dress jeans, a casual shirtjacket as it is usually cold, a scarf and boots but at night even when it is cold women wear skirts or tight jeans, tight top that is low cut and the highest heels they could find, and it does not matter the age or size, pretty much all the women dress that way which works perfectly in Colombia lots of beautiful women. Be prepared for a casual touching. Check with your consulate to see what the requirements are for you. If your girl sees them before the game, she will see you only as a player and that is the worst way to turn off her.