Looking for website to load faster

Hi currently the desktop version loads fast. but using the google page speed test shows very poor eprformance onphone loading.
i also used gtmetrix and pingdom. there are some too many http requests, and a couple of other thigns.
I am using autooptimazi, wp cache, imagify, and have used jetpack boost but the site gets complete undone.

the weblink is online-cbt.com if you want to check.
when someone build the website use elementor, and this is an old version. if it gets updated the website configurations goes. so please bare that in mind.
so the idea for the mobile version to be faster, and i am looking for a pricing.
please if you respond to the porject and intend to provide the service at a different rate please, state the rate you woudl charge. and please don't eb pushy