As of tomorrow . I will be adding a 3 to 5 yr old budgie to my flock . Also 2 Quails . That will be a much lovged addition to my Flock but a bit of help please on keeping this older budgie to live as long as it can ? like as is there any extra care it needs because it is a older budgie .

No extra attention is required except if the other birds are evenly paired. The new bird might want to mate when the others do. so fighting might erupt.