jQuery not available to other scripts

You’ve got two copies of some inline script

var $mcj = jQuery.noConflict(true);

inside a commented section ‘mc_embed_signup’. The ‘true’ here is removeAll:

removeAll
Type: Boolean
A Boolean indicating whether to remove all jQuery variables from the global scope (including jQuery itself).

You should track down this script and try and understand what it’s trying to do, or just remove the ‘true’ if you’re sure you don’t need it.