What type of freon does a 1993 honda civic use?

Can you tell a difference what type it uses like for example the ac lines if they are screw on or popped on??

r-12 fittings are smaller and are a screw on style while r-134a are a snap on quick connect design. typically a r-134a conversion is really nothing more than screwing on a different fitting over the old ones and recharging the system with r-134a. if it looks like you have large fittings screwed over an exsisting one on the line then it's been converted. if its just a lone fitting coming out of the line then it's still r-12.

If one of the ac lines break say the low side,will there still be some freon left in the compressor and or other parts?

the low side is where you put the freon in,so no.need to get it checked by qualified a/c technician.