Well it's a 94 Accord EX with VTEC 2.2L. When I start it up after it's done warming up or while I drive it the Engine rev up and down between about 750-1500RPM. Egr Valve or Idle control valve?

 

Idle control valve (IACV) on intake manifold.
Fast-idle valve (FITV) under throttle body.

Clean them out, & somewhere there's a thread about opening up the FITV & tightening something. (I haven't actually done this myself.)

Clean throttle body - any crud in the bore where the throttle closes?

Make sure the throttle cable & the throttle stop screw allow the throttle to close completely. Just in case some misguided mechanic has used them to adjust your idle speed.

Find & fix any vacuum leaks.

Search (probably in the DIY section?) for 'base idle'. There's a specific procedure. Don't just muck around with the adjustments, because the ECU will fight back & that's what causes the surging idle.