New to the engine modding thing
 

ok i bought a cheap car to get around in for a year a 90 hatch civic dx it has a 1.5 (i think) (i pick up the car thursday) n e ways can i dump a different head on it for what can i do 2 give it a little more power

Congrats on your new toy. :)
You could do mini-me swap, but from I understand they're not very reliable and pretty costly, although I will admit I don't know too much on that matter.
The better question is how much can you spend?
The most common swaps into a 4th gen are ZC, b16 and now a d16z6.
All have their pros and cons (some more than others) but it depends really on how much you can spend.

well im not sure but i beleave that in 1988-1991 the si's had i 1.6
and i was thinking about swapping the heads

I don't think this will work.
I'm not sure, but perhaps the oiling and cooling lines are different? Maybe the Gasket wouldn't fit?

Better swapping a b series. Good luck.

You could swap a VTEC head from a d16z6 or a d16y8, since they're also 1.6, but I have no clue how to go about doing that though...

Yes, you can put any D16 head on there. Any 1.6L will work and be totally reliable...VTEC or not.
From personal experience...

if i dump a new engine in it i want to dump a del sol engine
i think its a d16z6

Del Sol engine is the same as a 5th gen Si or EX engine. You can do a D16Y8 and D16Y7 swap too... Y7s are cheap, plentiful and reliable... most low mileage too... easy swap! Mini-me engines are plenty reliable, as reliable as your bottom end (that's gonna be the oldest thing in your engine).

dpfi - mpfi swap first thing to do