Update to PHP 7.0

Hi there. I would like to update the PHP to version 7..x.x, but there are 2 errors and some warning in some files of your them.
Please, may you help me to resolve?
Below the details:

FILE: /wp-content/themes/Aqua/includes/boc_widgets.php
—————————————————————————————–
FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 2 LINES
—————————————————————————————–
17 | WARNING | Use of deprecated PHP4 style class constructor is not supported since PHP 7.
99 | WARNING | Use of deprecated PHP4 style class constructor is not supported since PHP 7.
—————————————————————————————–

FILE: /wp-content/themes/Aqua/contact.php
—————————————————————————————–
FOUND 2 ERRORS AFFECTING 1 LINE
—————————————————————————————–
36 | ERROR | Extension ‘ereg’ is deprecated since PHP 5.3 and removed since PHP 7.0 – use pcre instead.
36 | ERROR | Function eregi() is deprecated since PHP 5.3 and removed since PHP 7.0; use preg_match instead
—————————————————————————————–

FILE: /wp-content/themes/Aqua/option-tree/includes/ot-cleanup-api.php
—————————————————————————————–
FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 2 LINES
—————————————————————————————–
126 | WARNING | INI directive ‘safe_mode’ is deprecated since PHP 5.3 and removed since PHP 5.4.
280 | WARNING | INI directive ‘safe_mode’ is deprecated since PHP 5.3 and removed since PHP 5.4.
—————————————————————————————–

Thank you!