Help! Don't know what to do!

Okay, so I’m making this FPS game but you don’t start out with any guns. Instead you walk up to a turret and shoot all the zombies. But I have no idea what to say in the script for the character to walk up to the turret and ‘enter’ it! I would like the player to push the space bar to enter it, and to exit it. PLEASE HELP!!! thank you

I would recommend going through some/all of the tutorials resources here: Unity Learn
Likely after completing them you’ll be able to achieve this on your own.