And it appears you've loaded both jQuery UI and jQuery datepicker. (I have my doubts, though, because your file is called "datepick"t the plugin is called "datepicker" - but maybe you just renamed the file?)
jQuery Datepicker is included as part of jQuery UI. If you load jQuery UI, don't also load jQuery Datepicker.
Alternately, if you have no other use for jQuery UI, you could load only datepicker.
BTW, both versions of jQuery that you are loading are obsolete. The latest is 3.1.1. However, jQuery UI can't use that yet, so you should use 2.2.4 or in case you need to support IE6,7,8 then use 1.12.4. (1.12.4 and 2.2.4 are functionally equivalent it is only the difference of old IE support.)