How to Do Simple Interactions?

Hi, I’m a bit new to Unity and JavaScript. I’m trying to make a game and I figured I’d try putting in actions that are context sensitive. How would I detect what’s in front of my “player character” within a certain radius of reach to then perform a specific action? (climb, jump, open, close, grab, etc)

Also, while I’m here, is there an effective way to a melee that can hit multiple targets without doing multiple calls that could possibly hitting the same object multiple times?

Look up Raycasting. You’d cast a ray whose length was your allowed interaction distance forward from the player and check what object it hits, then select the appropriate action.