Welcome! I hesitate to address you by your chosen handle as it seems (it could look) a bit rude? Do you have a real name we could use instead?
At any rate, we are glad to have you join our group!
It sounds as though you found quite the buy!! I wouldn't mind driving one of those for most of what I need to negotiate but I didn't see any with a reasonable number of miles and at that age it is hard to find one in solid shape.
You won't be able to use a ScanGauge on this model as the standards needed for one were not introduced until 1996, but you can still install some devices such as a vacuum gauge. I know that basjoos has hooked up something called a SuperMID to his '92 Civic to get a lot of the same type of information available from a SG. A quick look on Google turned up this (hopefully!) useful thread:
SuperMID DIY Install
Have a look at that and see if it might be something you'd be willing to tackle? I'm sure basjoos could offer some advice on that topic as well.
As for improving numbers, get the tires inflated up to the maximum rated sidewall! Lowered rolling resistance will help as the car won't need to work as hard to keep you at speed. Have a look at the excellent article called "Beating the EPA - The Why’s and how to Hypermile" by xcel -- it will give a great overview of the available techniques and get you started. You can find it at the top of the articles bar at the right on the home page of this site. The other articles there are also wonderful reading -- even the ones that seem to be just for hybrids have a lot of useful bits for non-hybrids as well.
What climate do you drive in? What is your commute like? Is it hilly or flat? Highway or backroads? What are your usual driving tactics? Do you like to follow the speed limits or are those "rough guidelines?"
The more you can tell us the better we can help you.
Once again, welcome!!