Help before i throw my computer out the window

Hello my future knights in shining armours. I'm currently trying to build my site and I'm realizing i am way less tech savvy than i thought. I'll link the template I'm trying to edit.

Every time I upload a photo, it stops being a cool slideshow and the photos just appear one of top of the other making no sense, looking ugly, and I have to scroll.

What am i doing wrong. I thought this site looked really easy to manage and I have like, photoshop, general adobe, and 3d experience so i'm losing it.

please please please help me

https://023856.cargo.site