Quick tips on stopping the rust on the cheap

hello FABO family,

Today is degrease and rust repair day. I am racking my brain because although I have little to no experience with body work/rust repair, I want to stop the cancer from getting any worse. To be clear, I am not trying to paint my car anytime soon, even though, it could use it. Can anyone suggest some specifics for me to sand and rattle can this small section of my engine bay? I was thinking of attaching a simple sandpaper or rough abrasive drill wheel to grind/sand down the rust and spray with some rust preventative. What do u think? It will be years before I get this car resprayed therefore I am merely trying to keep the rust from getting any worse over the next few years.

I really don’t know what direction to go in. The rust does not look to be going all the way through the metal. Preliminary look the metal seems to be pretty solid still underneath the current rust. No holes but a pretty good area of what I’d call more than surface rust. Pictures below....

Thanks in advance!