I was driving today and when I would slow down or start to take off the engine would revv up on its own then stop what causes this.

Engine sucking oil out of the crankcase among other things.

So what exactly is among other things and how do I go about fixing it

Read the link below and see if anything "jumps out" at you:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-8.html#post1415281