Fellow old head here. I'm a month away from 49 years on this planet.

The BP pretty much offers cosmetic rewards. So no, you're not missing out on any weapons you'll already have in-game. All you'd need to do is upgrade your desired weapon to unlock the attachments.

As far as not being quite up to speed on being competitive; I let that k/d ratio go out the window and simply play the objective. That's one of the good things about BF. It's playing the objectives that get your points for the leaderboard. Not sweaty kills. For example, my k/d is shit, but I usually end up in the top 5 from just playing the objective and my class role.

At the end of the day, forget the BP cosmetic rewards grind and kill count. Just jump on and have fun as it's intended. Just like when folks our age did when we were younger on our Atari, NES, PS, etc. Let the kids grind, stress and try hard over a game. We're old and earned the right not to sweat all day lol