Sigil: City of Doors

I know when you create a character you get languages...yet when you level up and get more intelligence can you select them some how?

or if you accidently choose say dwarf twice can that be changed?

or if you cancel the selection ?

(first one only applies to me number 2 will eventually due to I do things like that)

Can we get the Polyglot Epic feat?

DMs can add languages to a character, but can't remove or change them (as far as I know; maybe that's been changed though).
So if you accidentally exit out of it like I stupidly did when I made Raif, a DM will probably take pity on you and give you the languages you could obtain. Same thing if you pick something twice I suppose.
Far as giving more languages later on, it's possible mechanics-wise, but of course totally up to the DMs. But as you gain int, you can't just pick up new languages yourself, it has to be given to you.

In PnP, you must spend skill points or use a feat to get more languages past level 1. Some classes/prestige classes add languages, as well.

Or get the Epic Feat Polyglot!