rabid bite
"Target creature your [sic] control deals damage equal to its power to target creature you don't control"
can I cast this on a creature without flying or reach and make it deal damage to one with flying?
Yes, why would you expect any difficulty with that?
702.9. Flying
702.9a Flying is an evasion ability.
702.9b A creature with flying can’t be blocked except by creatures with flying and/or reach. A
creature with flying can block a creature with or without flying. (See rule 509, “Declare
Blockers Step,” and rule 702.17, “Reach.”)
702.9c Multiple instances of flying on the same creature are redundant.
Flying doesn't interfere with damage, just blocking. And your creature is unlikely to be blocking during the same turn you cast Rabid Bite anyway.
"Target creature your control deals damage equal to its power to target creature you don't control"
can I cast this on a creature without flying or reach and make it deal damage to one with flying?
Yes, why would you expect any difficulty with that?
Flying doesn't interfere with damage, just blocking. And your creature is unlikely to be blocking during the same turn you cast Rabid Bite anyway.