Just ask questions
Making friends later in life is no easy task, you need to somehow act like an adult, even though you have the humor of a kid. You don’t want to swear or curse to come off as rude or crass, but you also do not want to be stuck up and uptight.
It is indeed a difficult balancing act, which is why we would just suggest that you be yourself. It’s really the only way that you can make a real friend if you show them what you are like and not some manufactured version of you. That’s the key factor to making a real connection.