Promotion slider within a theme's php template

Hi everyone!

This is my first post here as a WordPress beginner, a little nervous here. Please forgive my mistakes in the following descriptions.

I have been trying for days to get a slider working for a website, tried several plugins and still can’t get it right. I am working locally on this website at the moment.

Here are the things I’m trying to do…

a. Place a slider within a front-page.php template of the theme I’m running (zerif-lite).
b. This promotion slider will essentially be a new section of this front page. There are already sections such as Our Focus and Our Team, each with their own theme mods and php files.
c. For each promotion, I’m hoping to have a graphic (approximately 400×300 px) + a title + short description.
d. Each promotion within this slider does not have to have their own page to link to.
e. Hopefully the layout and controls of this slider can be device responsive too
f. Autoplay

I understand these may be really hard for me to do as a beginner. I tried testimonial plugins, post sliders, image sliders, but so far none of them seem to be satisfying the above requirements. Image slider for example, means each promotion’s picture + text has to be included in one image file, which will not be device responsive.

I am rather clueless now about how to solve this. Any help would be greatly, greatly appreciated.

Below is a sketch that shows what I’m trying to make.
Promotion Slider Web Sketch
Promotion Slider Mobile Sketch