Push your limits or push yourself to the limits : 너의 한계를 밀어붙이다 or 한계를 밀어붙이다 (cuz we mostly omit the subject in sentence in spoken korean if possible)
Take a risk : 위험을 감수하다 (모험하다 is ok but not 100% accurate here)
Even if you're scared to take a risk sometimes you've gotta push your limits in order to reach your goal :
(네가) 위험을 감수하기 두렵더라도, 가끔은 (너의) 목표에 이르기 위해서 (네) 한계를 밀어붙여야 해.