Customize sliders

Pretty new to WordPress, so any, all, and detailed help would be greatly appreciated.

I would like to create a custom slider for my homepage/landing page–specifically, I would like to be able to add a filter over slider images, and change text color and alignment.

I did manage to upload my own images and add titles and descriptions by navigating to Theme Options > Homepage > Homepage slider. However, the “Custom slider” option asks to input shortcode for an existing slider.

I feel like I’ve clicked through most of the back end of the website and haven’t seen any options to create a custom slider. Where can I create a custom slider and corresponding shortcode, and do you have any other advice on this?

Thanks very much!