Son has existing pirate. Other son and I created new characters today. How do we meet up with the person that has the existing char? He seems to be in different instances than the two of us so we never see him to get a menu to group/friend.

No, we do not play Wizard101.

Sounds like they are in different realms, the subdivisions which lets places in the game not be overrun by too many pirates at once. Think like a hotel building, they are all in the hotel, and the rooms look the same, they are just in different rooms. They just need to move to the same one.
When you mouse over the top of the screen, you see drop down tabs. The one on the right, with the gear on it, gives the options menu. One of the tabs in there gives you the page for Realms (and if that Realm is busy, Areas that subdivide the realm further). The shortcut to get there quicker is Control key with M key.

You might want to look around in the options area while you are there. There are a lot of settings you may want to use, for things like labels on players and non-players, who follows you around, fast combat display, and having crew on tasks keep doing them with out having to order them to every time.