search bar options

i thought of having read this topic before but cant locate it. anyways, due to the immense growth of my forum, recently my members are always asking me if we can enable the search bar on our forum so they can find specific topics with ease. i explained to them that we are on a private mode because i dont want trolls messing up my forum. also, i notice that every time i click the search bar with my query on it, it just go to google. we might want to request also if you can enable the search bar without us going to public forum coz i want to screen every possible members that want to join. your quick response means so much to us. thank you so much.