catch your feet

Exactly how it sounds, the equivalent of saying "Don't trip", basically stop yourself from digging yourself into a deeper hole. Stop asking or worrying about something.

Guy: I'll ask her when the last time she got checked was
Guy2: Catch your feet dude shes going to get pissed if you keep asking her shit like that.

on your feet

it means wake up or stand up in a more army type

on your feet soldier we are leaving!