How to achieve this web design using HTML and CSS?

I'm currently interning and I was asked to replicate a design that looks like this. Considering I'm still new, I still don't know my way around web design. How can I achieve such boxes in the middle of the screen. I already know how to make forms and using validators, login pages, etc... My only issue is with the design that I don't know how to replicate. How should I start? Thank you in advance.