94 accord lx, what is the best offset as to not having too much space fromm tire to fender after lowering with coilovers?

 

Offset is nothing without width, as it is a measurement from the center of the wheel, not the outer lip.

For a 7" wheel, +32 would be about as low as you'll want to go with properly sized tires. If you roll your fenders/quarter panels, you'll be able to fit something a bit lower in offset or wider.