custom the style Elegant add link and change the text

Hi,
Can you please inform me how can i :

1- add the link for add the group and for the evenement like i have for add filter on the Elegant style (picture)

2- on the dashboard change the ( french traduction text), for example change friends by my contact, (i need to change the text on yellow color on the picture) (Elegant style)

Thank you in advance for your help.
Best regards,
Djam