How do you not grow a beard? I mean, it happens on it's own, right?. I gave in to nature a long time ago, to a degree. I mostly trim it. I can't even remember the last time I completely shaved, but I'd wager I was wearing a white collar for the occasion.
My advice would be to let it grow for a couple/few weeks, and then start trimming it so it has a chance to fill in and even up. After a couple/few months like that it should be about as full as it's going to get and you can decide if it's worth keeping and what length you'd ultimately like.
Takes me a few weeks. I have kept a very short beard over the last year. Gives me a little hair balance to the hair-challenged top of my head. My dad grows a beard in a couple of days. I always approach things like beards with humility. Enjoy and be proud of what god gave you. We’re all different.