"This focused identity helps a changeling pinpoint a particular skill or emotion. A changeling adventurer might have personas for many situations, including negotiation, investigation, and combat. Personas can be shared by multiple changelings; there might be three healers in a community, but whoever is on duty will adopt the persona of Tek, the kindly old medic"

So does this mean a changeling can have multiple personas and as they change personas so does their skills and attributes?

For example play rouge one session then switch to fighter next because their personas align that way?

Quote from Brian_Avery >>

I don't think they mean you can change races or classes (although you may appear to do so depending on what you look like), they just mean that certain skills and things might be associated with different personas.

Jo' rok might be a gruff, course, and violent person who likes to fight and you take his form whenever combat starts.

Mendolas might be adventurous and likes to see new places and you take his form whenever traveling.

Sybil might be a self-assured know it all who is skilled in many things and you take her form whenever you have to make a skill check.

This!   Great reply!

Changlings have a quirk where each of their different forms have different personalities and skills. How you choose to role play that is up to you. Mechanically, this is represented in the divergent persona racial trait which gives 1 tool proficiency that a specific personality is particularly adept at using.

Does changeling have dark vision 

A changeling does not have darkvision.