heya Nairda, im pretty sure your car's an ED, as im pretty sure EFs are only CRXs and imported civics?

As Andw0o said, there isnt much you can really do to the d15b4 dual carb motor, but a cheap mod would be the air intake.
crack open the airbox (the thing that says cv dual carb at the back of the engine bay) and make sure theres a filter inside, feel free to replace this with a k&n filter or any other filter (k&n had a consistently high flow rate from a recent autosalon test compared to other brands). then bring the filter to your local supermarket, head to the cooking utensils area, and find a baking tray that is just bigger than the filter. then bring it back to the original carby lid, line it up so that the filter sits entirely within the area of the baking tray, and drill a hole thru the centre so you it can be screwed on as a replacement lid. then yank out a really short screw driver (phillips no.2, shorter than 10cm in length), and inside the airbox there should be a metal flap near where the cold air intake is. remove that flap to reduce the air resistance and improve flow rate marginally. then fit the filter, screw on the baking tray, and viola, partially exposed air filter.
minus the filter, this should cost you less than $5 if you have all the tools (replacement filter might set you back 50).

other option is to do the dual motorbike filter mod listed elsewhere on these forums. and definitely get spark plugs and ignition leads just to make the carby a little more efficient.

aside from that, not much else you can do for straight line power short of sticking in a new motor or turbo.