Understandable, the hacking isn't the most intuitive thing going in blind, and sadly I never managed to build a tutorial in the game, so I had to leave the controls and explanations in the description, sorry.
As a short summary of it, basically each room has a letter + number code (A1, B3, C2, etc.) and you enter that into the keypad on the left, which'll change the room's code to a blue color (scanning) and then green (scanned). You can do this from anywhere and at any time.
All non-player actions also work off of the timer in the bottom left, for a pseudo-turn-based system. So when you select a room to hack, Neuro won't start scanning it until her next turn, and it'll finish scanning upon reaching the turn after that.
Scanning is extremely important because it's the only way to know if a guard (Evil) is in a room or not, and scanned rooms have their state guaranteed for a couple turns, which essentially means that an empty scanned room will remain empty while it remains scanned (green), and a scanned room that contains enemies will continue to contain those enemies for the same period. You can use this to lock guards in rooms or lock them out of rooms, and like that safely traverse the map.
I'm absolutely aiming for an in-game tutorial for the post-jam version, because many people misunderstood or got confused with the mechanics.