wordpress running slow- master slider does not work.

Hi

I just recently downloaded WordPress and installed Theme Trust template.
All fine, except its running very very slow. Nothing is loading properly.Also today the problem seemed to increase. We needed a good slide show controller. Master Slider came top for recommendation. The only thing is, that once I uploaded 3 images for a test with a video embedded file. Saved it, all good. Then copy and pasted the shortcode into the page, I wanted it to appear and nothing. Its not working properly at all. I must add I am not a webdesigner, but with logic and simple instructions I’ve created two layouts for the website. See link to my Master slider gallery https://www.illuminateproductions.co.uk/wordpress/wp-admin/admin.php?page=master-slider&action=edit&slider_id=3

Then see link to the page I was trying to add the shortcode to.
https://www.illuminateproductions.co.uk/wordpress/wp-admin/post.php?post=174&action=edit

Please tell me what I’m doing wrong. Are the images to big, should they be 2MBYTES max. Is there an actual limit for each image in the slide show?

Sorry for so many questions, I’m a little frustrated,would love to get this under my belt, so thats the hard part out of the way.

Hope to hear from you.

Angie.