Hi luc62ltt
For the image, you can change it in Backend >> Components >> Contact
With the intro message, you can find it in the language file of template:
/language/en-GB/en-GB.tpl_ja_blockk.ini
TPL_CONTACT_TITLE_FORM_CONTACT = "Have any Question? <br />Feel free to contact with us."
In case that you want to override this text, you can override it in Backend >> Manage >> Language overrides