We added each other on instagram now what

Hi I’m not super good at making friends and don’t understand certain social etiquette but I’ve been trying to put myself out there more and I talk to someone while we were at a club we hit it off had a lot of things in common and I could see us being friends however we added each other on instagram before we parted ways and now I’m not sure where to go from there should I send a message,what should it say idk I need help.