This is a difficult question to answer as every players experience with Beat Saber will be different, but this is what I would recommend. If you are new to the game and have just purchased it, dont worry about ghost glow until your timing becomes better during regular play. It was designed for people who already know how to play because they might get frustrated by waypoints if they didnt already understand them. However, if youre not sure when or even why your timing should improve then take some time off from playing and practice on that beatmap before going back in again.