Loading time homepage

Hi guys,
Thank you a lot for all the help with creating my website.
Now the website is slowly going to the end, so I am now looking to improve the loading time for the website.

http.//dev.paninternational.com.au/portalnew

the ‘normal’ pages are not a big problem, but the slider on the homepage is very slow. The different slider freeze sometimes, and after a few seconds they go further. I can’t minimize the size of the pictures because they need to be a good quality. What can I do to improve this loading time?
The video on top of Artistmanagement need also sometimes some loading time, but I can imagine that, it is a big size.
If you can give me some tips, I appreciate it a lot!