to be honest mate you could be or since you said you were decent at passing and catching you could be a good half back(scrum half) so im not sure but just try your best and keep cool and you will do fine! :)
Sorry to dump this responsibility on you but being the scum half pretty much means you dictate how your team attacks. Your main focus is when you choose to give the ball to the backs. passing and decision making is why you are there. never lob the ball up to anyone. a tip for tackling: grip onto a leg and don't let go, either they fall or slow down until your support comes. Having a powerful, accurate pass is one of the best things for a half back. Hopefully you've watched a few games on T.V
After front row and flyhalf, scrumhalf is pretty much the most important position on the team.
That's not for the worst players it's important if no one is there to pass the ball to the backs you can't play