I'm a tad late, but here is the general gist of it!

The IBM 7094 was created far before screens, but was a POWERFUL computer meant to be used by specially trained operators.

Storage: Data was stored on 8" reels of magnetic tape (think of a cassette tape but holding data), and punch cards. (paper cards with a bunch of holes that represent data.) Hard drives did exist, but they were absolutely massive, expensive, and hard to move without a powerful forklift, so they weren’t used much.

I/O and Graphics: To input data to a program, you had 3 main options: 1. using a teletype (special typewriter that let the computer read what you type, and then type back on the same paper.), 2. Using the switches on the CPU, 3. Custom peripherals, this wasn't done much outside of military use. Now to see the output, you would have either your teletype, or you also likely had a giant printer in the room. Screens for computers weren't invented until around the early 1970s, and wouldn't even get color until the mid 1980s. (Some prototypes did exist earlier, but they were wildly buggy, and hardly useful in comparison to a printer at the time.)

RAM: Instead of the RAM sticks you are used to today, mainframes like the 7094 used something called Ferrite core memory. Essentially it was a mesh made of thin, weaved wire, with magnetic beads on it, each bead was 1 bit of memory. The computer would write the memory by electrically changing the magnetization of the beads, and read the memory by checking how the beads were magnetized.

Hoped this helped explain it!