I'd recommend finding an easy, forgiving municipal course and play it every week. When you practice, imagine the shots count and focus on developing a quick, pre shot routine. Step behind the ball quickly, see the shot, step into the stance, check your body and ball alignment, one look at the target and hit it.
I've played with 20 handicaps who are a joy to play with because they step up and hit the ball quickly and played with low single digit handicaps and wanted to pull my hair out because they take so much time in their routines and in looking over putts. So, it's all about having a quick routine, paying attention to what other people are doing, then being ready and relatively quick when it's your turn.
As far as not being a very good player, the game makes fools of even the best players and no one really cares about your game or score but you. Go out and enjoy it, laugh at the bad shots and just worry about keeping the pace.